* [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation
@ 2019-01-01 23:20 Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 1/9] bpf: move {prev_,}insn_idx into verifier env Daniel Borkmann
` (8 more replies)
0 siblings, 9 replies; 12+ messages in thread
From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw)
To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann
This set fixes an out of bounds case under speculative execution
by implementing masking of pointer alu into the verifier. For
details please see the individual patches.
Thanks!
v1 -> v2:
- Typo fixes in commit msg and a comment, thanks David!
Daniel Borkmann (9):
bpf: move {prev_,}insn_idx into verifier env
bpf: move tmp variable into ax register in interpreter
bpf: enable access to ax register also from verifier rewrite
bpf: restrict map value pointer arithmetic for unprivileged
bpf: restrict stack pointer arithmetic for unprivileged
bpf: restrict unknown scalars of mixed signed bounds for unprivileged
bpf: fix check_map_access smin_value test when pointer contains offset
bpf: prevent out of bounds speculation on pointer arithmetic
bpf: add various test cases to selftests
include/linux/bpf_verifier.h | 12 +
include/linux/filter.h | 10 +-
kernel/bpf/core.c | 54 +-
kernel/bpf/verifier.c | 342 ++++++--
tools/testing/selftests/bpf/test_verifier.c | 1146 ++++++++++++++++++++++++++-
5 files changed, 1457 insertions(+), 107 deletions(-)
--
2.9.5
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH bpf v2 1/9] bpf: move {prev_,}insn_idx into verifier env 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 2/9] bpf: move tmp variable into ax register in interpreter Daniel Borkmann ` (7 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Move prev_insn_idx and insn_idx from the do_check() function into the verifier environment, so they can be read inside the various helper functions for handling the instructions. It's easier to put this into the environment rather than changing all call-sites only to pass it along. insn_idx is useful in particular since this later on allows to hold state in env->insn_aux_data[env->insn_idx]. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- include/linux/bpf_verifier.h | 2 ++ kernel/bpf/verifier.c | 76 ++++++++++++++++++++++---------------------- 2 files changed, 40 insertions(+), 38 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c233efc..3f84f3e 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -212,6 +212,8 @@ struct bpf_subprog_info { * one verifier_env per bpf_check() call */ struct bpf_verifier_env { + u32 insn_idx; + u32 prev_insn_idx; struct bpf_prog *prog; /* eBPF program being verified */ const struct bpf_verifier_ops *ops; struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 71d86e3..afa8515 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5650,7 +5650,6 @@ static int do_check(struct bpf_verifier_env *env) struct bpf_insn *insns = env->prog->insnsi; struct bpf_reg_state *regs; int insn_cnt = env->prog->len, i; - int insn_idx, prev_insn_idx = 0; int insn_processed = 0; bool do_print_state = false; @@ -5670,19 +5669,19 @@ static int do_check(struct bpf_verifier_env *env) BPF_MAIN_FUNC /* callsite */, 0 /* frameno */, 0 /* subprogno, zero == main subprog */); - insn_idx = 0; + for (;;) { struct bpf_insn *insn; u8 class; int err; - if (insn_idx >= insn_cnt) { + if (env->insn_idx >= insn_cnt) { verbose(env, "invalid insn idx %d insn_cnt %d\n", - insn_idx, insn_cnt); + env->insn_idx, insn_cnt); return -EFAULT; } - insn = &insns[insn_idx]; + insn = &insns[env->insn_idx]; class = BPF_CLASS(insn->code); if (++insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) { @@ -5692,7 +5691,7 @@ static int do_check(struct bpf_verifier_env *env) return -E2BIG; } - err = is_state_visited(env, insn_idx); + err = is_state_visited(env, env->insn_idx); if (err < 0) return err; if (err == 1) { @@ -5700,9 +5699,9 @@ static int do_check(struct bpf_verifier_env *env) if (env->log.level) { if (do_print_state) verbose(env, "\nfrom %d to %d: safe\n", - prev_insn_idx, insn_idx); + env->prev_insn_idx, env->insn_idx); else - verbose(env, "%d: safe\n", insn_idx); + verbose(env, "%d: safe\n", env->insn_idx); } goto process_bpf_exit; } @@ -5715,10 +5714,10 @@ static int do_check(struct bpf_verifier_env *env) if (env->log.level > 1 || (env->log.level && do_print_state)) { if (env->log.level > 1) - verbose(env, "%d:", insn_idx); + verbose(env, "%d:", env->insn_idx); else verbose(env, "\nfrom %d to %d:", - prev_insn_idx, insn_idx); + env->prev_insn_idx, env->insn_idx); print_verifier_state(env, state->frame[state->curframe]); do_print_state = false; } @@ -5729,20 +5728,20 @@ static int do_check(struct bpf_verifier_env *env) .private_data = env, }; - verbose_linfo(env, insn_idx, "; "); - verbose(env, "%d: ", insn_idx); + verbose_linfo(env, env->insn_idx, "; "); + verbose(env, "%d: ", env->insn_idx); print_bpf_insn(&cbs, insn, env->allow_ptr_leaks); } if (bpf_prog_is_dev_bound(env->prog->aux)) { - err = bpf_prog_offload_verify_insn(env, insn_idx, - prev_insn_idx); + err = bpf_prog_offload_verify_insn(env, env->insn_idx, + env->prev_insn_idx); if (err) return err; } regs = cur_regs(env); - env->insn_aux_data[insn_idx].seen = true; + env->insn_aux_data[env->insn_idx].seen = true; if (class == BPF_ALU || class == BPF_ALU64) { err = check_alu_op(env, insn); @@ -5768,13 +5767,13 @@ static int do_check(struct bpf_verifier_env *env) /* check that memory (src_reg + off) is readable, * the state of dst_reg will be updated by this func */ - err = check_mem_access(env, insn_idx, insn->src_reg, insn->off, - BPF_SIZE(insn->code), BPF_READ, - insn->dst_reg, false); + err = check_mem_access(env, env->insn_idx, insn->src_reg, + insn->off, BPF_SIZE(insn->code), + BPF_READ, insn->dst_reg, false); if (err) return err; - prev_src_type = &env->insn_aux_data[insn_idx].ptr_type; + prev_src_type = &env->insn_aux_data[env->insn_idx].ptr_type; if (*prev_src_type == NOT_INIT) { /* saw a valid insn @@ -5799,10 +5798,10 @@ static int do_check(struct bpf_verifier_env *env) enum bpf_reg_type *prev_dst_type, dst_reg_type; if (BPF_MODE(insn->code) == BPF_XADD) { - err = check_xadd(env, insn_idx, insn); + err = check_xadd(env, env->insn_idx, insn); if (err) return err; - insn_idx++; + env->insn_idx++; continue; } @@ -5818,13 +5817,13 @@ static int do_check(struct bpf_verifier_env *env) dst_reg_type = regs[insn->dst_reg].type; /* check that memory (dst_reg + off) is writeable */ - err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, - BPF_SIZE(insn->code), BPF_WRITE, - insn->src_reg, false); + err = check_mem_access(env, env->insn_idx, insn->dst_reg, + insn->off, BPF_SIZE(insn->code), + BPF_WRITE, insn->src_reg, false); if (err) return err; - prev_dst_type = &env->insn_aux_data[insn_idx].ptr_type; + prev_dst_type = &env->insn_aux_data[env->insn_idx].ptr_type; if (*prev_dst_type == NOT_INIT) { *prev_dst_type = dst_reg_type; @@ -5852,9 +5851,9 @@ static int do_check(struct bpf_verifier_env *env) } /* check that memory (dst_reg + off) is writeable */ - err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, - BPF_SIZE(insn->code), BPF_WRITE, - -1, false); + err = check_mem_access(env, env->insn_idx, insn->dst_reg, + insn->off, BPF_SIZE(insn->code), + BPF_WRITE, -1, false); if (err) return err; @@ -5872,9 +5871,9 @@ static int do_check(struct bpf_verifier_env *env) } if (insn->src_reg == BPF_PSEUDO_CALL) - err = check_func_call(env, insn, &insn_idx); + err = check_func_call(env, insn, &env->insn_idx); else - err = check_helper_call(env, insn->imm, insn_idx); + err = check_helper_call(env, insn->imm, env->insn_idx); if (err) return err; @@ -5887,7 +5886,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - insn_idx += insn->off + 1; + env->insn_idx += insn->off + 1; continue; } else if (opcode == BPF_EXIT) { @@ -5901,8 +5900,8 @@ static int do_check(struct bpf_verifier_env *env) if (state->curframe) { /* exit from nested function */ - prev_insn_idx = insn_idx; - err = prepare_func_exit(env, &insn_idx); + env->prev_insn_idx = env->insn_idx; + err = prepare_func_exit(env, &env->insn_idx); if (err) return err; do_print_state = true; @@ -5932,7 +5931,8 @@ static int do_check(struct bpf_verifier_env *env) if (err) return err; process_bpf_exit: - err = pop_stack(env, &prev_insn_idx, &insn_idx); + err = pop_stack(env, &env->prev_insn_idx, + &env->insn_idx); if (err < 0) { if (err != -ENOENT) return err; @@ -5942,7 +5942,7 @@ static int do_check(struct bpf_verifier_env *env) continue; } } else { - err = check_cond_jmp_op(env, insn, &insn_idx); + err = check_cond_jmp_op(env, insn, &env->insn_idx); if (err) return err; } @@ -5959,8 +5959,8 @@ static int do_check(struct bpf_verifier_env *env) if (err) return err; - insn_idx++; - env->insn_aux_data[insn_idx].seen = true; + env->insn_idx++; + env->insn_aux_data[env->insn_idx].seen = true; } else { verbose(env, "invalid BPF_LD mode\n"); return -EINVAL; @@ -5970,7 +5970,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - insn_idx++; + env->insn_idx++; } verbose(env, "processed %d insns (limit %d), stack depth ", -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 2/9] bpf: move tmp variable into ax register in interpreter 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 1/9] bpf: move {prev_,}insn_idx into verifier env Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 3/9] bpf: enable access to ax register also from verifier rewrite Daniel Borkmann ` (6 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run() into the hidden ax register. The latter is currently only used in JITs for constant blinding as a temporary scratch register, meaning the BPF interpreter will never see the use of ax. Therefore it is safe to use it for the cases where tmp has been used earlier. This is needed to later on allow restricted hidden use of ax in both interpreter and JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- include/linux/filter.h | 3 ++- kernel/bpf/core.c | 34 +++++++++++++++++----------------- 2 files changed, 19 insertions(+), 18 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 8c8544b..84a6a98 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -60,7 +60,8 @@ struct sock_reuseport; * constants. See JIT pre-step in bpf_jit_blind_constants(). */ #define BPF_REG_AX MAX_BPF_REG -#define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) +#define MAX_BPF_EXT_REG (MAX_BPF_REG + 1) +#define MAX_BPF_JIT_REG MAX_BPF_EXT_REG /* unused opcode to mark special call to bpf_tail_call() helper */ #define BPF_TAIL_CALL 0xf0 diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 38de580..a34312a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -54,6 +54,7 @@ #define DST regs[insn->dst_reg] #define SRC regs[insn->src_reg] #define FP regs[BPF_REG_FP] +#define AX regs[BPF_REG_AX] #define ARG1 regs[BPF_REG_ARG1] #define CTX regs[BPF_REG_CTX] #define IMM insn->imm @@ -1188,7 +1189,6 @@ bool bpf_opcode_in_insntable(u8 code) */ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) { - u64 tmp; #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z static const void *jumptable[256] = { @@ -1268,36 +1268,36 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) (*(s64 *) &DST) >>= IMM; CONT; ALU64_MOD_X: - div64_u64_rem(DST, SRC, &tmp); - DST = tmp; + div64_u64_rem(DST, SRC, &AX); + DST = AX; CONT; ALU_MOD_X: - tmp = (u32) DST; - DST = do_div(tmp, (u32) SRC); + AX = (u32) DST; + DST = do_div(AX, (u32) SRC); CONT; ALU64_MOD_K: - div64_u64_rem(DST, IMM, &tmp); - DST = tmp; + div64_u64_rem(DST, IMM, &AX); + DST = AX; CONT; ALU_MOD_K: - tmp = (u32) DST; - DST = do_div(tmp, (u32) IMM); + AX = (u32) DST; + DST = do_div(AX, (u32) IMM); CONT; ALU64_DIV_X: DST = div64_u64(DST, SRC); CONT; ALU_DIV_X: - tmp = (u32) DST; - do_div(tmp, (u32) SRC); - DST = (u32) tmp; + AX = (u32) DST; + do_div(AX, (u32) SRC); + DST = (u32) AX; CONT; ALU64_DIV_K: DST = div64_u64(DST, IMM); CONT; ALU_DIV_K: - tmp = (u32) DST; - do_div(tmp, (u32) IMM); - DST = (u32) tmp; + AX = (u32) DST; + do_div(AX, (u32) IMM); + DST = (u32) AX; CONT; ALU_END_TO_BE: switch (IMM) { @@ -1553,7 +1553,7 @@ STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ { \ u64 stack[stack_size / sizeof(u64)]; \ - u64 regs[MAX_BPF_REG]; \ + u64 regs[MAX_BPF_EXT_REG]; \ \ FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ ARG1 = (u64) (unsigned long) ctx; \ @@ -1566,7 +1566,7 @@ static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ const struct bpf_insn *insn) \ { \ u64 stack[stack_size / sizeof(u64)]; \ - u64 regs[MAX_BPF_REG]; \ + u64 regs[MAX_BPF_EXT_REG]; \ \ FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ BPF_R1 = r1; \ -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 3/9] bpf: enable access to ax register also from verifier rewrite 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 1/9] bpf: move {prev_,}insn_idx into verifier env Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 2/9] bpf: move tmp variable into ax register in interpreter Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 4/9] bpf: restrict map value pointer arithmetic for unprivileged Daniel Borkmann ` (5 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Right now we are using BPF ax register in JIT for constant blinding as well as in interpreter as temporary variable. Verifier will not be able to use it simply because its use will get overridden from the former in bpf_jit_blind_insn(). However, it can be made to work in that blinding will be skipped if there is prior use in either source or destination register on the instruction. Taking constraints of ax into account, the verifier is then open to use it in rewrites under some constraints. Note, ax register already has mappings in every eBPF JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- include/linux/filter.h | 7 +------ kernel/bpf/core.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 84a6a98..ad106d8 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -53,12 +53,7 @@ struct sock_reuseport; #define BPF_REG_D BPF_REG_8 /* data, callee-saved */ #define BPF_REG_H BPF_REG_9 /* hlen, callee-saved */ -/* Kernel hidden auxiliary/helper register for hardening step. - * Only used by eBPF JITs. It's nothing more than a temporary - * register that JITs use internally, only that here it's part - * of eBPF instructions that have been rewritten for blinding - * constants. See JIT pre-step in bpf_jit_blind_constants(). - */ +/* Kernel hidden auxiliary/helper register. */ #define BPF_REG_AX MAX_BPF_REG #define MAX_BPF_EXT_REG (MAX_BPF_REG + 1) #define MAX_BPF_JIT_REG MAX_BPF_EXT_REG diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index a34312a..f908b93 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -858,6 +858,26 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from, BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); + /* Constraints on AX register: + * + * AX register is inaccessible from user space. It is mapped in + * all JITs, and used here for constant blinding rewrites. It is + * typically "stateless" meaning its contents are only valid within + * the executed instruction, but not across several instructions. + * There are a few exceptions however which are further detailed + * below. + * + * Constant blinding is only used by JITs, not in the interpreter. + * The interpreter uses AX in some occasions as a local temporary + * register e.g. in DIV or MOD instructions. + * + * In restricted circumstances, the verifier can also use the AX + * register for rewrites as long as they do not interfere with + * the above cases! + */ + if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) + goto out; + if (from->imm == 0 && (from->code == (BPF_ALU | BPF_MOV | BPF_K) || from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 4/9] bpf: restrict map value pointer arithmetic for unprivileged 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (2 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 3/9] bpf: enable access to ax register also from verifier rewrite Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 5/9] bpf: restrict stack " Daniel Borkmann ` (4 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Restrict map value pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a map value pointer as a destination it will simulate a check_map_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. We use this later on for masking any pointer arithmetic with the remainder of the map value space. The likelihood of breaking any existing real-world unprivileged eBPF program is very small for this corner case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index afa8515..4da8c73 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3249,6 +3249,17 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, __update_reg_bounds(dst_reg); __reg_deduce_bounds(dst_reg); __reg_bound_offset(dst_reg); + + /* For unprivileged we require that resulting offset must be in bounds + * in order to be able to sanitize access later on. + */ + if (!env->allow_ptr_leaks && dst_reg->type == PTR_TO_MAP_VALUE && + check_map_access(env, dst, dst_reg->off, 1, false)) { + verbose(env, "R%d pointer arithmetic of map value goes out of range, prohibited for !root\n", + dst); + return -EACCES; + } + return 0; } -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 5/9] bpf: restrict stack pointer arithmetic for unprivileged 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (3 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 4/9] bpf: restrict map value pointer arithmetic for unprivileged Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 6/9] bpf: restrict unknown scalars of mixed signed bounds " Daniel Borkmann ` (3 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Restrict stack pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a stack pointer as a destination we simulate a check_stack_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. This is analog to map value pointer arithmetic and needed for masking later on. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 63 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 41 insertions(+), 22 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4da8c73..9ac205d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1387,6 +1387,31 @@ static int check_stack_read(struct bpf_verifier_env *env, } } +static int check_stack_access(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, + int off, int size) +{ + /* Stack accesses must be at a fixed offset, so that we + * can determine what type of data were returned. See + * check_stack_read(). + */ + if (!tnum_is_const(reg->var_off)) { + char tn_buf[48]; + + tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); + verbose(env, "variable stack access var_off=%s off=%d size=%d", + tn_buf, off, size); + return -EACCES; + } + + if (off >= 0 || off < -MAX_BPF_STACK) { + verbose(env, "invalid stack off=%d size=%d\n", off, size); + return -EACCES; + } + + return 0; +} + /* check read/write into map element returned by bpf_map_lookup_elem() */ static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off, int size, bool zero_size_allowed) @@ -1954,24 +1979,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn } } else if (reg->type == PTR_TO_STACK) { - /* stack accesses must be at a fixed offset, so that we can - * determine what type of data were returned. - * See check_stack_read(). - */ - if (!tnum_is_const(reg->var_off)) { - char tn_buf[48]; - - tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose(env, "variable stack access var_off=%s off=%d size=%d", - tn_buf, off, size); - return -EACCES; - } off += reg->var_off.value; - if (off >= 0 || off < -MAX_BPF_STACK) { - verbose(env, "invalid stack off=%d size=%d\n", off, - size); - return -EACCES; - } + err = check_stack_access(env, reg, off, size); + if (err) + return err; state = func(env, reg); err = update_stack_depth(env, state, off); @@ -3253,11 +3264,19 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, /* For unprivileged we require that resulting offset must be in bounds * in order to be able to sanitize access later on. */ - if (!env->allow_ptr_leaks && dst_reg->type == PTR_TO_MAP_VALUE && - check_map_access(env, dst, dst_reg->off, 1, false)) { - verbose(env, "R%d pointer arithmetic of map value goes out of range, prohibited for !root\n", - dst); - return -EACCES; + if (!env->allow_ptr_leaks) { + if (dst_reg->type == PTR_TO_MAP_VALUE && + check_map_access(env, dst, dst_reg->off, 1, false)) { + verbose(env, "R%d pointer arithmetic of map value goes out of range, " + "prohibited for !root\n", dst); + return -EACCES; + } else if (dst_reg->type == PTR_TO_STACK && + check_stack_access(env, dst_reg, dst_reg->off + + dst_reg->var_off.value, 1)) { + verbose(env, "R%d stack pointer arithmetic goes out of range, " + "prohibited for !root\n", dst); + return -EACCES; + } } return 0; -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 6/9] bpf: restrict unknown scalars of mixed signed bounds for unprivileged 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (4 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 5/9] bpf: restrict stack " Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 7/9] bpf: fix check_map_access smin_value test when pointer contains offset Daniel Borkmann ` (2 subsequent siblings) 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann For unknown scalars of mixed signed bounds, meaning their smin_value is negative and their smax_value is positive, we need to reject arithmetic with pointer to map value. For unprivileged the goal is to mask every map pointer arithmetic and this cannot reliably be done when it is unknown at verification time whether the scalar value is negative or positive. Given this is a corner case, the likelihood of breaking should be very small. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9ac205d..eebbc03 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3081,8 +3081,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value; u64 umin_val = off_reg->umin_value, umax_val = off_reg->umax_value, umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value; + u32 dst = insn->dst_reg, src = insn->src_reg; u8 opcode = BPF_OP(insn->code); - u32 dst = insn->dst_reg; dst_reg = ®s[dst]; @@ -3115,6 +3115,13 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, verbose(env, "R%d pointer arithmetic on %s prohibited\n", dst, reg_type_str[ptr_reg->type]); return -EACCES; + case PTR_TO_MAP_VALUE: + if (!env->allow_ptr_leaks && !known && (smin_val < 0) != (smax_val < 0)) { + verbose(env, "R%d has unknown scalar with mixed signed bounds, pointer arithmetic with it prohibited for !root\n", + off_reg == dst_reg ? dst : src); + return -EACCES; + } + /* fall-through */ default: break; } -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 7/9] bpf: fix check_map_access smin_value test when pointer contains offset 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (5 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 6/9] bpf: restrict unknown scalars of mixed signed bounds " Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic Daniel Borkmann 2019-01-01 23:20 ` [PATCH bpf v2 9/9] bpf: add various test cases to selftests Daniel Borkmann 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann In check_map_access() we probe actual bounds through __check_map_access() with offset of reg->smin_value + off for lower bound and offset of reg->umax_value + off for the upper bound. However, even though the reg->smin_value could have a negative value, the final result of the sum with off could be positive when pointer arithmetic with known and unknown scalars is combined. In this case we reject the program with an error such as "R<x> min value is negative, either use unsigned index or do a if (index >=0) check." even though the access itself would be fine. Therefore extend the check to probe whether the actual resulting reg->smin_value + off is less than zero. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index eebbc03..8e5da1c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1443,13 +1443,17 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, */ if (env->log.level) print_verifier_state(env, state); + /* The minimum value is only important with signed * comparisons where we can't assume the floor of a * value is 0. If we are using signed variables for our * index'es we need to make sure that whatever we use * will have a set floor within our range. */ - if (reg->smin_value < 0) { + if (reg->smin_value < 0 && + (reg->smin_value == S64_MIN || + (off + reg->smin_value != (s64)(s32)(off + reg->smin_value)) || + reg->smin_value + off < 0)) { verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", regno); return -EACCES; -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (6 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 7/9] bpf: fix check_map_access smin_value test when pointer contains offset Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 2019-01-02 22:11 ` Jakub Kicinski 2019-01-01 23:20 ` [PATCH bpf v2 9/9] bpf: add various test cases to selftests Daniel Borkmann 8 siblings, 1 reply; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Jann reported that the original commit back in b2157399cc98 ("bpf: prevent out-of-bounds speculation") was not sufficient to stop CPU from speculating out of bounds memory access: While b2157399cc98 only focussed on masking array map access for unprivileged users for tail calls and data access such that the user provided index gets sanitized from BPF program and syscall side, there is still a more generic form affected from BPF programs that applies to most maps that hold user data in relation to dynamic map access when dealing with unknown scalars or "slow" known scalars as access offset, for example: - Load a map value pointer into R6 - Load an index into R7 - Do a slow computation (e.g. with a memory dependency) that loads a limit into R8 (e.g. load the limit from a map for high latency, then mask it to make the verifier happy) - Exit if R7 >= R8 (mispredicted branch) - Load R0 = R6[R7] - Load R0 = R6[R0] For unknown scalars there are two options in the BPF verifier where we could derive knowledge from in order to guarantee safe access to the memory: i) While </>/<=/>= variants won't allow to derive any lower or upper bounds from the unknown scalar where it would be safe to add it to the map value pointer, it is possible through ==/!= test however. ii) another option is to transform the unknown scalar into a known scalar, for example, through ALU ops combination such as R &= <imm> followed by R |= <imm> or any similar combination where the original information from the unknown scalar would be destroyed entirely leaving R with a constant. The initial slow load still precedes the latter ALU ops on that register, so the CPU executes speculatively from that point. Once we have the known scalar, any compare operation would work then. A third option only involving registers with known scalars could be crafted as described in [0] where a CPU port (e.g. Slow Int unit) would be filled with many dependent computations such that the subsequent condition depending on its outcome has to wait for evaluation on its execution port and thereby executing speculatively if the speculated code can be scheduled on a different execution port, or any other form of mistraining as described in [1], for example. Given this is not limited to only unknown scalars, not only map but also stack access is affected since both is accessible for unprivileged users and could potentially be used for out of bounds access under speculation. In order to prevent any of these cases, the verifier is now sanitizing pointer arithmetic on the offset such that any out of bounds speculation would be masked in a way where the pointer arithmetic result in the destination register will stay unchanged, meaning offset masked into zero similar as in array_index_nospec() case. With regards to implementation, there are three options that were considered: i) new insn for sanitation, ii) push/pop insn and sanitation as inlined BPF, iii) reuse of ax register and sanitation as inlined BPF. Option i) has the downside that we end up using from reserved bits in the opcode space, but also that we would require each JIT to emit masking as native arch opcodes meaning mitigation would have slow adoption till everyone implements it eventually which is counter-productive. Option ii) and iii) have both in common that a temporary register is needed in order to implement the sanitation as inlined BPF since we are not allowed to modify the source register. While a push / pop insn in ii) would be useful to have in any case, it requires once again that every JIT needs to implement it first. While possible, amount of changes needed would also be unsuitable for a -stable patch. Therefore, the path which has fewer changes, less BPF instructions for the mitigation and does not require anything to be changed in the JITs is option iii) which this work is pursuing. The ax register is already mapped to a register in all JITs (modulo arm32 where it's mapped to stack as various other BPF registers there) and used in constant blinding for JITs-only so far. It can be reused for verifier rewrites under certain constraints. The interpreter's tmp "register" has therefore been remapped into extending the register set with hidden ax register and reusing that for a number of instructions that needed the prior temporary variable internally (e.g. div, mod). This allows for zero increase in stack space usage in the interpreter, and enables (restricted) generic use in rewrites otherwise as long as such a patchlet does not make use of these instructions. The sanitation mask is dynamic and relative to the offset the map value or stack pointer currently holds. There are various cases that need to be taken under consideration for the masking, e.g. such operation could look as follows: ptr += val or val += ptr or ptr -= val. Thus, the value to be sanitized could reside either in source or in destination register, and the limit is different depending on whether the ALU op is addition or subtraction and depending on the current known and bounded offset. The limit is derived as follows: limit := max_value_size - (smin_value + off). For subtraction: limit := umax_value + off. This holds because we do not allow any pointer arithmetic that would temporarily go out of bounds or would have an unknown value with mixed signed bounds where it is unclear at verification time whether the actual runtime value would be either negative or positive. For example, we have a derived map pointer value with constant offset and bounded one, so limit based on smin_value works because the verifier requires that statically analyzed arithmetic on the pointer must be in bounds, and thus it checks if resulting smin_value + off and umax_value + off is still within map value bounds at time of arithmetic in addition to time of access. Similarly, for the case of stack access we derive the limit as follows: MAX_BPF_STACK + off for subtraction and -off for the case of addition where off := ptr_reg->off + ptr_reg->var_off.value. Subtraction is a special case for the masking which can be in form of ptr += -val, ptr -= -val, or ptr -= val. In the first two cases where we know that the value is negative, we need to temporarily negate the value in order to do the sanitation on a positive value where we later swap the ALU op, and restore original source register if the value was in source. The sanitation of pointer arithmetic alone is still not fully sufficient as is, since a scenario like the following could happen ... PTR += 0x1000 (e.g. K-based imm) PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON PTR += 0x1000 PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON [...] ... which under speculation could end up as ... PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] [...] ... and therefore still access out of bounds. To prevent such case, the verifier is also analyzing safety for potential out of bounds access under speculative execution. Meaning, it is also simulating pointer access under truncation. We therefore "branch off" and push the current verification state after the ALU operation with known 0 to the verification stack for later analysis. Given the current path analysis succeeded it is likely that the one under speculation can be pruned. In any case, it is also subject to existing complexity limits and therefore anything beyond this point will be rejected. In terms of pruning, it needs to be ensured that the verification state from speculative execution simulation must never prune a non-speculative execution path, therefore, we mark verifier state accordingly at the time of push_stack(). If verifier detects out of bounds access under speculative execution from one of the possible paths that includes a truncation, it will reject such program. Given we mask every reg-based pointer arithmetic for unprivileged programs, we've been looking into how it could affect real-world programs in terms of size increase. As the majority of programs are targeted for privileged-only use case, we've unconditionally enabled masking (with its alu restrictions on top of it) for privileged programs for the sake of testing in order to check i) whether they get rejected in its current form, and ii) by how much the number of instructions and size will increase. We've tested this by using Katran, Cilium and test_l4lb from the kernel selftests. For Katran we've evaluated balancer_kern.o, Cilium bpf_lxc.o and an older test object bpf_lxc_opt_-DUNKNOWN.o and l4lb we've used test_l4lb.o as well as test_l4lb_noinline.o. We found that none of the programs got rejected by the verifier with this change, and that impact is rather minimal to none. balancer_kern.o had 13,904 bytes (1,738 insns) xlated and 7,797 bytes JITed before and after the change. Most complex program in bpf_lxc.o had 30,544 bytes (3,817 insns) xlated and 18,538 bytes JITed before and after and none of the other tail call programs in bpf_lxc.o had any changes either. For the older bpf_lxc_opt_-DUNKNOWN.o object we found a small increase from 20,616 bytes (2,576 insns) and 12,536 bytes JITed before to 20,664 bytes (2,582 insns) and 12,558 bytes JITed after the change. Other programs from that object file had similar small increase. Both test_l4lb.o had no change and remained at 6,544 bytes (817 insns) xlated and 3,401 bytes JITed and for test_l4lb_noinline.o constant at 5,080 bytes (634 insns) xlated and 3,313 bytes JITed. This can be explained in that LLVM typically optimizes stack based pointer arithmetic by using K-based operations and that use of dynamic map access is not overly frequent. However, in future we may decide to optimize the algorithm further under known guarantees from branch and value speculation. Latter seems also unclear in terms of prediction heuristics that today's CPUs apply as well as whether there could be collisions in e.g. the predictor's Value History/Pattern Table for triggering out of bounds access, thus masking is performed unconditionally at this point but could be subject to relaxation later on. We were generally also brainstorming various other approaches for mitigation, but the blocker was always lack of available registers at runtime and/or overhead for runtime tracking of limits belonging to a specific pointer. Thus, we found this to be minimally intrusive under given constraints. With that in place, a simple example with sanitized access on unprivileged load at post-verification time looks as follows: # bpftool prog dump xlated id 282 [...] 28: (79) r1 = *(u64 *)(r7 +0) 29: (79) r2 = *(u64 *)(r7 +8) 30: (57) r1 &= 15 31: (79) r3 = *(u64 *)(r0 +4608) 32: (57) r3 &= 1 33: (47) r3 |= 1 34: (2d) if r2 > r3 goto pc+19 35: (b4) (u32) r11 = (u32) 20479 | 36: (1f) r11 -= r2 | Dynamic sanitation for pointer 37: (4f) r11 |= r2 | arithmetic with registers 38: (87) r11 = -r11 | containing bounded or known 39: (c7) r11 s>>= 63 | scalars in order to prevent 40: (5f) r11 &= r2 | out of bounds speculation. 41: (0f) r4 += r11 | 42: (71) r4 = *(u8 *)(r4 +0) 43: (6f) r4 <<= r1 [...] For the case where the scalar sits in the destination register as opposed to the source register, the following code is emitted for the above example: [...] 16: (b4) (u32) r11 = (u32) 20479 17: (1f) r11 -= r2 18: (4f) r11 |= r2 19: (87) r11 = -r11 20: (c7) r11 s>>= 63 21: (5f) r2 &= r11 22: (0f) r2 += r0 23: (61) r0 = *(u32 *)(r2 +0) [...] JIT blinding example with non-conflicting use of r10: [...] d5: je 0x0000000000000106 _ d7: mov 0x0(%rax),%edi | da: mov $0xf153246,%r10d | Index load from map value and e0: xor $0xf153259,%r10 | (const blinded) mask with 0x1f. e7: and %r10,%rdi |_ ea: mov $0x2f,%r10d | f0: sub %rdi,%r10 | Sanitized addition. Both use r10 f3: or %rdi,%r10 | but do not interfere with each f6: neg %r10 | other. (Neither do these instructions f9: sar $0x3f,%r10 | interfere with the use of ax as temp fd: and %r10,%rdi | in interpreter.) 100: add %rax,%rdi |_ 103: mov 0x0(%rdi),%eax [...] Tested that it fixes Jann's reproducer, and also checked that test_verifier and test_progs suite with interpreter, JIT and JIT with hardening enabled on x86-64 and arm64 runs successfully. [0] Speculose: Analyzing the Security Implications of Speculative Execution in CPUs, Giorgi Maisuradze and Christian Rossow, https://arxiv.org/pdf/1801.04084.pdf [1] A Systematic Evaluation of Transient Execution Attacks and Defenses, Claudio Canella, Jo Van Bulck, Michael Schwarz, Moritz Lipp, Benjamin von Berg, Philipp Ortner, Frank Piessens, Dmitry Evtyushkin, Daniel Gruss, https://arxiv.org/pdf/1811.05441.pdf Fixes: b2157399cc98 ("bpf: prevent out-of-bounds speculation") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- include/linux/bpf_verifier.h | 10 +++ kernel/bpf/verifier.c | 191 +++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 195 insertions(+), 6 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 3f84f3e..27b7494 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -148,6 +148,7 @@ struct bpf_verifier_state { /* call stack tracking */ struct bpf_func_state *frame[MAX_CALL_FRAMES]; u32 curframe; + bool speculative; }; #define bpf_get_spilled_reg(slot, frame) \ @@ -167,15 +168,24 @@ struct bpf_verifier_state_list { struct bpf_verifier_state_list *next; }; +/* Possible states for alu_state member. */ +#define BPF_ALU_SANITIZE_SRC 1U +#define BPF_ALU_SANITIZE_DST 2U +#define BPF_ALU_NEG_VALUE (1U << 2) +#define BPF_ALU_SANITIZE (BPF_ALU_SANITIZE_SRC | \ + BPF_ALU_SANITIZE_DST) + struct bpf_insn_aux_data { union { enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ unsigned long map_state; /* pointer/poison value for maps */ s32 call_imm; /* saved imm field of call insn */ + u32 alu_limit; /* limit for add/sub register with pointer */ }; int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ int sanitize_stack_off; /* stack slot to be cleared */ bool seen; /* this insn was processed by the verifier */ + u8 alu_state; /* used in combination with alu_limit */ }; #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8e5da1c..448a828 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -710,6 +710,7 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state, free_func_state(dst_state->frame[i]); dst_state->frame[i] = NULL; } + dst_state->speculative = src->speculative; dst_state->curframe = src->curframe; for (i = 0; i <= src->curframe; i++) { dst = dst_state->frame[i]; @@ -754,7 +755,8 @@ static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx, } static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env, - int insn_idx, int prev_insn_idx) + int insn_idx, int prev_insn_idx, + bool speculative) { struct bpf_verifier_state *cur = env->cur_state; struct bpf_verifier_stack_elem *elem; @@ -772,6 +774,7 @@ static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env, err = copy_verifier_state(&elem->st, cur); if (err) goto err; + elem->st.speculative |= speculative; if (env->stack_size > BPF_COMPLEXITY_LIMIT_STACK) { verbose(env, "BPF program is too complex\n"); goto err; @@ -3067,6 +3070,102 @@ static bool check_reg_sane_offset(struct bpf_verifier_env *env, return true; } +static struct bpf_insn_aux_data *cur_aux(struct bpf_verifier_env *env) +{ + return &env->insn_aux_data[env->insn_idx]; +} + +static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg, + u32 *ptr_limit, u8 opcode, bool off_is_neg) +{ + bool mask_to_left = (opcode == BPF_ADD && off_is_neg) || + (opcode == BPF_SUB && !off_is_neg); + u32 off; + + switch (ptr_reg->type) { + case PTR_TO_STACK: + off = ptr_reg->off + ptr_reg->var_off.value; + if (mask_to_left) + *ptr_limit = MAX_BPF_STACK + off; + else + *ptr_limit = -off; + return 0; + case PTR_TO_MAP_VALUE: + if (mask_to_left) { + *ptr_limit = ptr_reg->umax_value + ptr_reg->off; + } else { + off = ptr_reg->smin_value + ptr_reg->off; + *ptr_limit = ptr_reg->map_ptr->value_size - off; + } + return 0; + default: + return -EINVAL; + } +} + +static int sanitize_ptr_alu(struct bpf_verifier_env *env, + struct bpf_insn *insn, + const struct bpf_reg_state *ptr_reg, + struct bpf_reg_state *dst_reg, + bool off_is_neg) +{ + struct bpf_verifier_state *vstate = env->cur_state; + struct bpf_insn_aux_data *aux = cur_aux(env); + bool ptr_is_dst_reg = ptr_reg == dst_reg; + u8 opcode = BPF_OP(insn->code); + u32 alu_state, alu_limit; + struct bpf_reg_state tmp; + bool ret; + + if (env->allow_ptr_leaks || BPF_SRC(insn->code) == BPF_K) + return 0; + + /* We already marked aux for masking from non-speculative + * paths, thus we got here in the first place. We only care + * to explore bad access from here. + */ + if (vstate->speculative) + goto do_sim; + + alu_state = off_is_neg ? BPF_ALU_NEG_VALUE : 0; + alu_state |= ptr_is_dst_reg ? + BPF_ALU_SANITIZE_SRC : BPF_ALU_SANITIZE_DST; + + if (retrieve_ptr_limit(ptr_reg, &alu_limit, opcode, off_is_neg)) + return 0; + + /* If we arrived here from different branches with different + * limits to sanitize, then this won't work. + */ + if (aux->alu_state && + (aux->alu_state != alu_state || + aux->alu_limit != alu_limit)) + return -EACCES; + + /* Corresponding fixup done in fixup_bpf_calls(). */ + aux->alu_state = alu_state; + aux->alu_limit = alu_limit; + +do_sim: + /* Simulate and find potential out-of-bounds access under + * speculative execution from truncation as a result of + * masking when off was not within expected range. If off + * sits in dst, then we temporarily need to move ptr there + * to simulate dst (== 0) +/-= ptr. Needed, for example, + * for cases where we use K-based arithmetic in one direction + * and truncated reg-based in the other in order to explore + * bad access. + */ + if (!ptr_is_dst_reg) { + tmp = *dst_reg; + *dst_reg = *ptr_reg; + } + ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true); + if (!ptr_is_dst_reg) + *dst_reg = tmp; + return !ret ? -EFAULT : 0; +} + /* Handles arithmetic on a pointer and a scalar: computes new min/max and var_off. * Caller should also handle BPF_MOV case separately. * If we return -EACCES, caller may want to try again treating pointer as a @@ -3087,6 +3186,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value; u32 dst = insn->dst_reg, src = insn->src_reg; u8 opcode = BPF_OP(insn->code); + int ret; dst_reg = ®s[dst]; @@ -3142,6 +3242,11 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, switch (opcode) { case BPF_ADD: + ret = sanitize_ptr_alu(env, insn, ptr_reg, dst_reg, smin_val < 0); + if (ret < 0) { + verbose(env, "R%d tried to add from different maps or paths\n", dst); + return ret; + } /* We can take a fixed offset as long as it doesn't overflow * the s32 'off' field */ @@ -3192,6 +3297,11 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } break; case BPF_SUB: + ret = sanitize_ptr_alu(env, insn, ptr_reg, dst_reg, smin_val < 0); + if (ret < 0) { + verbose(env, "R%d tried to sub from different maps or paths\n", dst); + return ret; + } if (dst_reg == off_reg) { /* scalar -= pointer. Creates an unknown scalar */ verbose(env, "R%d tried to subtract pointer from scalar\n", @@ -4389,7 +4499,8 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, } } - other_branch = push_stack(env, *insn_idx + insn->off + 1, *insn_idx); + other_branch = push_stack(env, *insn_idx + insn->off + 1, *insn_idx, + false); if (!other_branch) return -EFAULT; other_branch_regs = other_branch->frame[other_branch->curframe]->regs; @@ -5499,6 +5610,13 @@ static bool states_equal(struct bpf_verifier_env *env, if (old->curframe != cur->curframe) return false; + /* Verification state from speculative execution simulation + * must never prune a non-speculative execution one. + */ + if (old->speculative != cur->speculative || + (old->speculative && !cur->speculative)) + return false; + /* for states to be equal callsites have to be the same * and all frame states need to be equivalent */ @@ -5530,6 +5648,11 @@ static int propagate_liveness(struct bpf_verifier_env *env, vparent->curframe, vstate->curframe); return -EFAULT; } + + /* Don't propagate to non-speculative parent. */ + if (vparent->speculative != vstate->speculative) + return 0; + /* Propagate read liveness of registers... */ BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); /* We don't need to worry about FP liveness because it's read-only */ @@ -5700,6 +5823,7 @@ static int do_check(struct bpf_verifier_env *env) if (!state) return -ENOMEM; state->curframe = 0; + state->speculative = false; state->frame[0] = kzalloc(sizeof(struct bpf_func_state), GFP_KERNEL); if (!state->frame[0]) { kfree(state); @@ -5739,8 +5863,10 @@ static int do_check(struct bpf_verifier_env *env) /* found equivalent state, can prune the search */ if (env->log.level) { if (do_print_state) - verbose(env, "\nfrom %d to %d: safe\n", - env->prev_insn_idx, env->insn_idx); + verbose(env, "\nfrom %d to %d%s: safe\n", + env->prev_insn_idx, env->insn_idx, + env->cur_state->speculative ? + " (speculative execution)" : ""); else verbose(env, "%d: safe\n", env->insn_idx); } @@ -5757,8 +5883,10 @@ static int do_check(struct bpf_verifier_env *env) if (env->log.level > 1) verbose(env, "%d:", env->insn_idx); else - verbose(env, "\nfrom %d to %d:", - env->prev_insn_idx, env->insn_idx); + verbose(env, "\nfrom %d to %d%s:", + env->prev_insn_idx, env->insn_idx, + env->cur_state->speculative ? + " (speculative execution)" : ""); print_verifier_state(env, state->frame[state->curframe]); do_print_state = false; } @@ -6750,6 +6878,57 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) continue; } + if (insn->code == (BPF_ALU64 | BPF_ADD | BPF_X) || + insn->code == (BPF_ALU64 | BPF_SUB | BPF_X)) { + const u8 code_add = BPF_ALU64 | BPF_ADD | BPF_X; + const u8 code_sub = BPF_ALU64 | BPF_SUB | BPF_X; + struct bpf_insn insn_buf[16]; + struct bpf_insn *patch = &insn_buf[0]; + bool issrc, isneg; + u32 off_reg; + + aux = &env->insn_aux_data[i + delta]; + if (!aux->alu_state) + continue; + + isneg = aux->alu_state & BPF_ALU_NEG_VALUE; + issrc = (aux->alu_state & BPF_ALU_SANITIZE) == + BPF_ALU_SANITIZE_SRC; + + off_reg = issrc ? insn->src_reg : insn->dst_reg; + if (isneg) + *patch++ = BPF_ALU64_IMM(BPF_MUL, off_reg, -1); + *patch++ = BPF_MOV32_IMM(BPF_REG_AX, aux->alu_limit - 1); + *patch++ = BPF_ALU64_REG(BPF_SUB, BPF_REG_AX, off_reg); + *patch++ = BPF_ALU64_REG(BPF_OR, BPF_REG_AX, off_reg); + *patch++ = BPF_ALU64_IMM(BPF_NEG, BPF_REG_AX, 0); + *patch++ = BPF_ALU64_IMM(BPF_ARSH, BPF_REG_AX, 63); + if (issrc) { + *patch++ = BPF_ALU64_REG(BPF_AND, BPF_REG_AX, + off_reg); + insn->src_reg = BPF_REG_AX; + } else { + *patch++ = BPF_ALU64_REG(BPF_AND, off_reg, + BPF_REG_AX); + } + if (isneg) + insn->code = insn->code == code_add ? + code_sub : code_add; + *patch++ = *insn; + if (issrc && isneg) + *patch++ = BPF_ALU64_IMM(BPF_MUL, off_reg, -1); + cnt = patch - insn_buf; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + if (insn->code != (BPF_JMP | BPF_CALL)) continue; if (insn->src_reg == BPF_PSEUDO_CALL) -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic 2019-01-01 23:20 ` [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic Daniel Borkmann @ 2019-01-02 22:11 ` Jakub Kicinski 2019-01-02 23:37 ` Daniel Borkmann 0 siblings, 1 reply; 12+ messages in thread From: Jakub Kicinski @ 2019-01-02 22:11 UTC (permalink / raw) To: Daniel Borkmann; +Cc: ast, jannh, davem, netdev On Wed, 2 Jan 2019 00:20:45 +0100, Daniel Borkmann wrote: > Jann reported that the original commit back in b2157399cc98 > ("bpf: prevent out-of-bounds speculation") was not sufficient > to stop CPU from speculating out of bounds memory access: > While b2157399cc98 only focussed on masking array map access > for unprivileged users for tail calls and data access such > that the user provided index gets sanitized from BPF program > and syscall side, there is still a more generic form affected > from BPF programs that applies to most maps that hold user > data in relation to dynamic map access when dealing with > unknown scalars or "slow" known scalars as access offset... > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 8e5da1c..448a828 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -5499,6 +5610,13 @@ static bool states_equal(struct bpf_verifier_env *env, > if (old->curframe != cur->curframe) > return false; > > + /* Verification state from speculative execution simulation > + * must never prune a non-speculative execution one. > + */ > + if (old->speculative != cur->speculative || > + (old->speculative && !cur->speculative)) > + return false; nit: if I read this correctly it looks more conservative than the comment suggests. The second case (old->speculative && !cur->speculative) implies the first case (old->speculative != cur->speculative). Perhaps: if (old->speculative && !cur->speculative) Or: if (old->speculative > cur->speculative) > + > /* for states to be equal callsites have to be the same > * and all frame states need to be equivalent > */ > @@ -5530,6 +5648,11 @@ static int propagate_liveness(struct bpf_verifier_env *env, > vparent->curframe, vstate->curframe); > return -EFAULT; > } > + > + /* Don't propagate to non-speculative parent. */ > + if (vparent->speculative != vstate->speculative) I haven't thought this trough fully, but is this really necessary? Do we assume the CPU will not speculate twice? It seems not impossible to have a register only accessed on the speculation path, and therefore if we don't propagate liveness non-speculative walk may prune speculative checks. > + return 0; > + > /* Propagate read liveness of registers... */ > BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); > /* We don't need to worry about FP liveness because it's read-only */ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic 2019-01-02 22:11 ` Jakub Kicinski @ 2019-01-02 23:37 ` Daniel Borkmann 0 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-02 23:37 UTC (permalink / raw) To: Jakub Kicinski; +Cc: ast, jannh, davem, netdev On 01/02/2019 11:11 PM, Jakub Kicinski wrote: > On Wed, 2 Jan 2019 00:20:45 +0100, Daniel Borkmann wrote: >> Jann reported that the original commit back in b2157399cc98 >> ("bpf: prevent out-of-bounds speculation") was not sufficient >> to stop CPU from speculating out of bounds memory access: >> While b2157399cc98 only focussed on masking array map access >> for unprivileged users for tail calls and data access such >> that the user provided index gets sanitized from BPF program >> and syscall side, there is still a more generic form affected >> from BPF programs that applies to most maps that hold user >> data in relation to dynamic map access when dealing with >> unknown scalars or "slow" known scalars as access offset... > >> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c >> index 8e5da1c..448a828 100644 >> --- a/kernel/bpf/verifier.c >> +++ b/kernel/bpf/verifier.c >> @@ -5499,6 +5610,13 @@ static bool states_equal(struct bpf_verifier_env *env, >> if (old->curframe != cur->curframe) >> return false; >> >> + /* Verification state from speculative execution simulation >> + * must never prune a non-speculative execution one. >> + */ >> + if (old->speculative != cur->speculative || >> + (old->speculative && !cur->speculative)) >> + return false; > > nit: if I read this correctly it looks more conservative than the > comment suggests. > > The second case (old->speculative && !cur->speculative) implies > the first case (old->speculative != cur->speculative). > Perhaps: > > if (old->speculative && !cur->speculative) > > Or: > > if (old->speculative > cur->speculative) Agree, and first one looks more readable. >> + >> /* for states to be equal callsites have to be the same >> * and all frame states need to be equivalent >> */ >> @@ -5530,6 +5648,11 @@ static int propagate_liveness(struct bpf_verifier_env *env, >> vparent->curframe, vstate->curframe); >> return -EFAULT; >> } >> + >> + /* Don't propagate to non-speculative parent. */ >> + if (vparent->speculative != vstate->speculative) > > I haven't thought this trough fully, but is this really necessary? > Do we assume the CPU will not speculate twice? It seems not impossible > to have a register only accessed on the speculation path, and therefore > if we don't propagate liveness non-speculative walk may prune > speculative checks. This indeed needs to be removed from the patch, excellent catch; we definitely don't want to run the risk of a reg being marked non-init in such case. I'll spin v3 with both fixed up. Thanks for review! >> + return 0; >> + >> /* Propagate read liveness of registers... */ >> BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); >> /* We don't need to worry about FP liveness because it's read-only */ ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH bpf v2 9/9] bpf: add various test cases to selftests 2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann ` (7 preceding siblings ...) 2019-01-01 23:20 ` [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic Daniel Borkmann @ 2019-01-01 23:20 ` Daniel Borkmann 8 siblings, 0 replies; 12+ messages in thread From: Daniel Borkmann @ 2019-01-01 23:20 UTC (permalink / raw) To: ast; +Cc: jannh, davem, netdev, Daniel Borkmann Add various map value pointer related test cases to test_verifier kselftest to reflect recent changes and improve test coverage. The tests include basic masking functionality, unprivileged behavior on pointer arithmetic which goes oob, mixed bounds tests, negative unknown scalar but resulting positive offset for access and helper range, handling of arithmetic from multiple maps, various masking scenarios with subsequent map value access and others including two test cases from Jann Horn for prior fixes. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- tools/testing/selftests/bpf/test_verifier.c | 1146 ++++++++++++++++++++++++++- 1 file changed, 1124 insertions(+), 22 deletions(-) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 33f7d38..10d4444 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -23,6 +23,7 @@ #include <stdbool.h> #include <sched.h> #include <limits.h> +#include <assert.h> #include <sys/capability.h> @@ -2577,6 +2578,7 @@ static struct bpf_test tests[] = { }, .result = REJECT, .errstr = "invalid stack off=-79992 size=8", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", }, { "PTR_TO_STACK store/load - out of bounds high", @@ -3104,6 +3106,8 @@ static struct bpf_test tests[] = { BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8), BPF_EXIT_INSN(), }, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .result_unpriv = REJECT, .result = ACCEPT, }, { @@ -3206,6 +3210,243 @@ static struct bpf_test tests[] = { .retval_unpriv = 2, }, { + "PTR_TO_STACK check high 1", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -1), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK check high 2", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ST_MEM(BPF_B, BPF_REG_1, -1, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, -1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK check high 3", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 0), + BPF_ST_MEM(BPF_B, BPF_REG_1, -1, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, -1), + BPF_EXIT_INSN(), + }, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .result_unpriv = REJECT, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK check high 4", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 0), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "invalid stack off=0 size=1", + .result = REJECT, + }, + { + "PTR_TO_STACK check high 5", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, (1 << 29) - 1), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off", + }, + { + "PTR_TO_STACK check high 6", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, (1 << 29) - 1), + BPF_ST_MEM(BPF_B, BPF_REG_1, SHRT_MAX, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, SHRT_MAX), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off", + }, + { + "PTR_TO_STACK check high 7", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, (1 << 29) - 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, (1 << 29) - 1), + BPF_ST_MEM(BPF_B, BPF_REG_1, SHRT_MAX, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, SHRT_MAX), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "fp pointer offset", + }, + { + "PTR_TO_STACK check low 1", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -512), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK check low 2", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -513), + BPF_ST_MEM(BPF_B, BPF_REG_1, 1, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 1), + BPF_EXIT_INSN(), + }, + .result_unpriv = REJECT, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK check low 3", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -513), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "invalid stack off=-513 size=1", + .result = REJECT, + }, + { + "PTR_TO_STACK check low 4", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, INT_MIN), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "math between fp pointer", + }, + { + "PTR_TO_STACK check low 5", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -((1 << 29) - 1)), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off", + }, + { + "PTR_TO_STACK check low 6", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -((1 << 29) - 1)), + BPF_ST_MEM(BPF_B, BPF_REG_1, SHRT_MIN, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, SHRT_MIN), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off", + }, + { + "PTR_TO_STACK check low 7", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -((1 << 29) - 1)), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -((1 << 29) - 1)), + BPF_ST_MEM(BPF_B, BPF_REG_1, SHRT_MIN, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, SHRT_MIN), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", + .errstr = "fp pointer offset", + }, + { + "PTR_TO_STACK mixed reg/k, 1", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, -3), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK mixed reg/k, 2", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, -3), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_5, -6), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 42, + }, + { + "PTR_TO_STACK mixed reg/k, 3", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, -3), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = -3, + }, + { + "PTR_TO_STACK reg", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_MOV64_IMM(BPF_REG_2, -3), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .result_unpriv = REJECT, + .errstr_unpriv = "invalid stack off=0 size=1", + .result = ACCEPT, + .retval = 42, + }, + { "stack pointer arithmetic", .insns = { BPF_MOV64_IMM(BPF_REG_1, 4), @@ -6610,7 +6851,446 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, { - "map access: known scalar += value_ptr", + "map access: known scalar += value_ptr from different maps", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, len)), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 3), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 1, 2), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_16b = { 5 }, + .fixup_map_array_48b = { 8 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R1 tried to add from different maps", + .retval = 1, + }, + { + "map access: value_ptr -= known scalar from different maps", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, len)), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 3), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 1, 2), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_16b = { 5 }, + .fixup_map_array_48b = { 8 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 min value is outside of the array range", + .retval = 1, + }, + { + "map access: known scalar += value_ptr from different maps, but same value properties", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, len)), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 3), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 1, 2), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_48b = { 5 }, + .fixup_map_array_48b = { 8 }, + .result = ACCEPT, + .retval = 1, + }, + { + "map access: value_ptr += known scalar, upper oob arith, test 1", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_MOV64_IMM(BPF_REG_1, 48), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: value_ptr += known scalar, upper oob arith, test 2", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_MOV64_IMM(BPF_REG_1, 49), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: value_ptr += known scalar, upper oob arith, test 3", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_MOV64_IMM(BPF_REG_1, 47), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: value_ptr -= known scalar, lower oob arith, test 1", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5), + BPF_MOV64_IMM(BPF_REG_1, 47), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 48), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = REJECT, + .errstr = "R0 min value is outside of the array range", + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + }, + { + "map access: value_ptr -= known scalar, lower oob arith, test 2", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + BPF_MOV64_IMM(BPF_REG_1, 47), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 48), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: value_ptr -= known scalar, lower oob arith, test 3", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5), + BPF_MOV64_IMM(BPF_REG_1, 47), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 47), + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: known scalar += value_ptr", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 1, + }, + { + "map access: value_ptr += known scalar, 1", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 1, + }, + { + "map access: value_ptr += known scalar, 2", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 49), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = REJECT, + .errstr = "invalid access to map value", + }, + { + "map access: value_ptr += known scalar, 3", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, -1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = REJECT, + .errstr = "invalid access to map value", + }, + { + "map access: value_ptr += known scalar, 4", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + BPF_MOV64_IMM(BPF_REG_1, 5), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, -2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, -1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 1, + }, + { + "map access: value_ptr += known scalar, 5", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, (6 + 1) * sizeof(int)), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 0xabcdef12, + }, + { + "map access: value_ptr += known scalar, 6", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5), + BPF_MOV64_IMM(BPF_REG_1, (3 + 1) * sizeof(int)), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 3 * sizeof(int)), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 0xabcdef12, + }, + { + "map access: unknown scalar += value_ptr, 1", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 1, + }, + { + "map access: unknown scalar += value_ptr, 2", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 31), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .retval = 0xabcdef12, + }, + { + "map access: unknown scalar += value_ptr, 3", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8), + BPF_MOV64_IMM(BPF_REG_1, -1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 31), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 3 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", + .retval = 0xabcdef12, + }, + { + "map access: unknown scalar += value_ptr, 4", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), @@ -6618,19 +7298,22 @@ static struct bpf_test tests[] = { BPF_LD_MAP_FD(BPF_REG_1, 0), BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), - BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), - BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6), + BPF_MOV64_IMM(BPF_REG_1, 19), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 31), BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), - BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), - BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0), BPF_EXIT_INSN(), }, .fixup_map_array_48b = { 3 }, - .result = ACCEPT, - .retval = 1, + .result = REJECT, + .errstr = "R1 max value is outside of the array range", + .errstr_unpriv = "R1 pointer arithmetic of map value goes out of range", }, { - "map access: value_ptr += known scalar", + "map access: value_ptr += unknown scalar, 1", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), @@ -6638,8 +7321,9 @@ static struct bpf_test tests[] = { BPF_LD_MAP_FD(BPF_REG_1, 0), BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), - BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), - BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf), BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), BPF_MOV64_IMM(BPF_REG_0, 1), @@ -6650,7 +7334,7 @@ static struct bpf_test tests[] = { .retval = 1, }, { - "map access: unknown scalar += value_ptr", + "map access: value_ptr += unknown scalar, 2", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), @@ -6659,19 +7343,18 @@ static struct bpf_test tests[] = { BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), - BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), - BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf), - BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0), - BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0), - BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 31), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0), BPF_EXIT_INSN(), }, .fixup_map_array_48b = { 3 }, .result = ACCEPT, - .retval = 1, + .retval = 0xabcdef12, }, { - "map access: value_ptr += unknown scalar", + "map access: value_ptr += unknown scalar, 3", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), @@ -6679,13 +7362,20 @@ static struct bpf_test tests[] = { BPF_LD_MAP_FD(BPF_REG_1, 0), BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), - BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4), - BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 11), + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 8), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 16), BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf), - BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), - BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_3, 1), + BPF_ALU64_IMM(BPF_OR, BPF_REG_3, 1), + BPF_JMP_REG(BPF_JGT, BPF_REG_2, BPF_REG_3, 4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_3), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_JMP_IMM(BPF_JA, 0, 0, -3), }, .fixup_map_array_48b = { 3 }, .result = ACCEPT, @@ -6770,6 +7460,8 @@ static struct bpf_test tests[] = { }, .fixup_map_array_48b = { 3 }, .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", .retval = 1, }, { @@ -6837,6 +7529,8 @@ static struct bpf_test tests[] = { }, .fixup_map_array_48b = { 3 }, .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", .retval = 1, }, { @@ -8376,6 +9070,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8400,6 +9095,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8426,6 +9122,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R8 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8451,6 +9148,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R8 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8499,6 +9197,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8570,6 +9269,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8621,6 +9321,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8648,6 +9349,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8674,6 +9376,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8703,6 +9406,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R7 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8733,6 +9437,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 4 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { @@ -8761,6 +9466,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "unbounded min value", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, .result_unpriv = REJECT, }, @@ -8813,9 +9519,39 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", + .errstr_unpriv = "R1 has unknown scalar with mixed signed bounds", .result = REJECT, }, { + "check subtraction on pointers for unpriv", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LD_MAP_FD(BPF_REG_ARG1, 0), + BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_ARG2, 0, 9), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_9, BPF_REG_FP), + BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_0), + BPF_LD_MAP_FD(BPF_REG_ARG1, 0), + BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_ARG2, 0, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_8b = { 1, 9 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R9 pointer -= pointer prohibited", + }, + { "bounds check based on zero-extended MOV", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), @@ -9146,6 +9882,36 @@ static struct bpf_test tests[] = { .result = REJECT }, { + "bounds check after 32-bit right shift with 64-bit input", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6), + /* r1 = 2 */ + BPF_MOV64_IMM(BPF_REG_1, 2), + /* r1 = 1<<32 */ + BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 31), + /* r1 = 0 (NOT 2!) */ + BPF_ALU32_IMM(BPF_RSH, BPF_REG_1, 31), + /* r1 = 0xffff'fffe (NOT 0!) */ + BPF_ALU32_IMM(BPF_SUB, BPF_REG_1, 2), + /* computes OOB pointer */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + /* OOB access */ + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0), + /* exit */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_8b = { 3 }, + .errstr = "R0 invalid mem access", + .result = REJECT, + }, + { "bounds check map access with off+size signed 32bit overflow. test1", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), @@ -9185,6 +9951,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "pointer offset 1073741822", + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", .result = REJECT }, { @@ -9206,6 +9973,7 @@ static struct bpf_test tests[] = { }, .fixup_map_hash_8b = { 3 }, .errstr = "pointer offset -1073741822", + .errstr_unpriv = "R0 pointer arithmetic of map value goes out of range", .result = REJECT }, { @@ -9377,6 +10145,7 @@ static struct bpf_test tests[] = { BPF_EXIT_INSN() }, .errstr = "fp pointer offset 1073741822", + .errstr_unpriv = "R1 stack pointer arithmetic goes out of range", .result = REJECT }, { @@ -13719,6 +14488,328 @@ static struct bpf_test tests[] = { .insn_processed = 15, }, { + "masking, test out of bounds 1", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 5), + BPF_MOV32_IMM(BPF_REG_2, 5 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 2", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 1), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 3", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0xffffffff), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 4", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0xffffffff), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 5", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, -1), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 6", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, -1), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 7", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 5), + BPF_MOV32_IMM(BPF_REG_2, 5 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 8", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 9", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0xffffffff), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 10", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0xffffffff), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 11", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -1), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test out of bounds 12", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -1), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test in bounds 1", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 4), + BPF_MOV32_IMM(BPF_REG_2, 5 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 4, + }, + { + "masking, test in bounds 2", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test in bounds 3", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0xfffffffe), + BPF_MOV32_IMM(BPF_REG_2, 0xffffffff - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0xfffffffe, + }, + { + "masking, test in bounds 4", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0xabcde), + BPF_MOV32_IMM(BPF_REG_2, 0xabcdef - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0xabcde, + }, + { + "masking, test in bounds 5", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 0), + BPF_MOV32_IMM(BPF_REG_2, 1 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { + "masking, test in bounds 6", + .insns = { + BPF_MOV32_IMM(BPF_REG_1, 46), + BPF_MOV32_IMM(BPF_REG_2, 47 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_1), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 46, + }, + { + "masking, test in bounds 7", + .insns = { + BPF_MOV64_IMM(BPF_REG_3, -46), + BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, -1), + BPF_MOV32_IMM(BPF_REG_2, 47 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_3), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_3), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_3, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_3), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 46, + }, + { + "masking, test in bounds 8", + .insns = { + BPF_MOV64_IMM(BPF_REG_3, -47), + BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, -1), + BPF_MOV32_IMM(BPF_REG_2, 47 - 1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_3), + BPF_ALU64_REG(BPF_OR, BPF_REG_2, BPF_REG_3), + BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0), + BPF_ALU64_IMM(BPF_ARSH, BPF_REG_2, 63), + BPF_ALU64_REG(BPF_AND, BPF_REG_3, BPF_REG_2), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_3), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .retval = 0, + }, + { "reference tracking in call: free reference in subprog and outside", .insns = { BPF_SK_LOOKUP, @@ -14413,6 +15504,16 @@ static int create_map(uint32_t type, uint32_t size_key, return fd; } +static void update_map(int fd, int index) +{ + struct test_val value = { + .index = (6 + 1) * sizeof(int), + .foo[6] = 0xabcdef12, + }; + + assert(!bpf_map_update_elem(fd, &index, &value, 0)); +} + static int create_prog_dummy1(enum bpf_prog_type prog_type) { struct bpf_insn prog[] = { @@ -14564,6 +15665,7 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type, if (*fixup_map_array_48b) { map_fds[3] = create_map(BPF_MAP_TYPE_ARRAY, sizeof(int), sizeof(struct test_val), 1); + update_map(map_fds[3], 0); do { prog[*fixup_map_array_48b].imm = map_fds[3]; fixup_map_array_48b++; -- 2.9.5 ^ permalink raw reply related [flat|nested] 12+ messages in thread
end of thread, other threads:[~2019-01-02 23:37 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
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2019-01-01 23:20 [PATCH bpf v2 0/9] bpf fix to prevent oob under speculation Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 1/9] bpf: move {prev_,}insn_idx into verifier env Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 2/9] bpf: move tmp variable into ax register in interpreter Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 3/9] bpf: enable access to ax register also from verifier rewrite Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 4/9] bpf: restrict map value pointer arithmetic for unprivileged Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 5/9] bpf: restrict stack " Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 6/9] bpf: restrict unknown scalars of mixed signed bounds " Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 7/9] bpf: fix check_map_access smin_value test when pointer contains offset Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 8/9] bpf: prevent out of bounds speculation on pointer arithmetic Daniel Borkmann
2019-01-02 22:11 ` Jakub Kicinski
2019-01-02 23:37 ` Daniel Borkmann
2019-01-01 23:20 ` [PATCH bpf v2 9/9] bpf: add various test cases to selftests Daniel Borkmann
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