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From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: bpf@vger.kernel.org
Cc: "Alexei Starovoitov" <ast@kernel.org>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>
Subject: [PATCH bpf-next v4 02/13] bpf: Move check_ptr_off_reg before check_map_access
Date: Sat,  9 Apr 2022 15:02:52 +0530	[thread overview]
Message-ID: <20220409093303.499196-3-memxor@gmail.com> (raw)
In-Reply-To: <20220409093303.499196-1-memxor@gmail.com>

Some functions in next patch want to use this function, and those
functions will be called by check_map_access, hence move it before
check_map_access.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 kernel/bpf/verifier.c | 76 +++++++++++++++++++++----------------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9c1a02b82ecd..71827d14724a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3469,6 +3469,44 @@ static int check_mem_region_access(struct bpf_verifier_env *env, u32 regno,
 	return 0;
 }
 
+static int __check_ptr_off_reg(struct bpf_verifier_env *env,
+			       const struct bpf_reg_state *reg, int regno,
+			       bool fixed_off_ok)
+{
+	/* Access to this pointer-typed register or passing it to a helper
+	 * is only allowed in its original, unmodified form.
+	 */
+
+	if (reg->off < 0) {
+		verbose(env, "negative offset %s ptr R%d off=%d disallowed\n",
+			reg_type_str(env, reg->type), regno, reg->off);
+		return -EACCES;
+	}
+
+	if (!fixed_off_ok && reg->off) {
+		verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n",
+			reg_type_str(env, reg->type), regno, reg->off);
+		return -EACCES;
+	}
+
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "variable %s access var_off=%s disallowed\n",
+			reg_type_str(env, reg->type), tn_buf);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+int check_ptr_off_reg(struct bpf_verifier_env *env,
+		      const struct bpf_reg_state *reg, int regno)
+{
+	return __check_ptr_off_reg(env, reg, regno, false);
+}
+
 /* check read/write into a map element with possible variable offset */
 static int check_map_access(struct bpf_verifier_env *env, u32 regno,
 			    int off, int size, bool zero_size_allowed)
@@ -3980,44 +4018,6 @@ static int get_callee_stack_depth(struct bpf_verifier_env *env,
 }
 #endif
 
-static int __check_ptr_off_reg(struct bpf_verifier_env *env,
-			       const struct bpf_reg_state *reg, int regno,
-			       bool fixed_off_ok)
-{
-	/* Access to this pointer-typed register or passing it to a helper
-	 * is only allowed in its original, unmodified form.
-	 */
-
-	if (reg->off < 0) {
-		verbose(env, "negative offset %s ptr R%d off=%d disallowed\n",
-			reg_type_str(env, reg->type), regno, reg->off);
-		return -EACCES;
-	}
-
-	if (!fixed_off_ok && reg->off) {
-		verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n",
-			reg_type_str(env, reg->type), regno, reg->off);
-		return -EACCES;
-	}
-
-	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
-		char tn_buf[48];
-
-		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-		verbose(env, "variable %s access var_off=%s disallowed\n",
-			reg_type_str(env, reg->type), tn_buf);
-		return -EACCES;
-	}
-
-	return 0;
-}
-
-int check_ptr_off_reg(struct bpf_verifier_env *env,
-		      const struct bpf_reg_state *reg, int regno)
-{
-	return __check_ptr_off_reg(env, reg, regno, false);
-}
-
 static int __check_buffer_access(struct bpf_verifier_env *env,
 				 const char *buf_info,
 				 const struct bpf_reg_state *reg,
-- 
2.35.1


  parent reply	other threads:[~2022-04-09  9:32 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-09  9:32 [PATCH bpf-next v4 00/13] Introduce typed pointer support in BPF maps Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` [PATCH bpf-next v4 01/13] bpf: Make btf_find_field more generic Kumar Kartikeya Dwivedi
2022-04-11 20:20   ` Joanne Koong
2022-04-12 19:48     ` Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` Kumar Kartikeya Dwivedi [this message]
2022-04-11 20:28   ` [PATCH bpf-next v4 02/13] bpf: Move check_ptr_off_reg before check_map_access Joanne Koong
2022-04-09  9:32 ` [PATCH bpf-next v4 03/13] bpf: Allow storing unreferenced kptr in map Kumar Kartikeya Dwivedi
2022-04-12  0:32   ` Joanne Koong
2022-04-12 19:16     ` Kumar Kartikeya Dwivedi
2022-04-12 23:56       ` Joanne Koong
2022-04-13  5:50         ` Kumar Kartikeya Dwivedi
2022-04-13  5:41   ` kernel test robot
2022-04-09  9:32 ` [PATCH bpf-next v4 04/13] bpf: Tag argument to be released in bpf_func_proto Kumar Kartikeya Dwivedi
2022-04-12 18:16   ` Joanne Koong
2022-04-12 20:11     ` Kumar Kartikeya Dwivedi
2022-04-13 18:33       ` Joanne Koong
2022-04-13 18:39         ` Joanne Koong
2022-04-09  9:32 ` [PATCH bpf-next v4 05/13] bpf: Allow storing referenced kptr in map Kumar Kartikeya Dwivedi
2022-04-12 23:05   ` Joanne Koong
2022-04-13  5:36     ` Kumar Kartikeya Dwivedi
2022-04-13  5:54       ` Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` [PATCH bpf-next v4 06/13] bpf: Prevent escaping of kptr loaded from maps Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` [PATCH bpf-next v4 07/13] bpf: Adapt copy_map_value for multiple offset case Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` [PATCH bpf-next v4 08/13] bpf: Populate pairs of btf_id and destructor kfunc in btf Kumar Kartikeya Dwivedi
2022-04-09  9:32 ` [PATCH bpf-next v4 09/13] bpf: Wire up freeing of referenced kptr Kumar Kartikeya Dwivedi
2022-04-09  9:33 ` [PATCH bpf-next v4 10/13] bpf: Teach verifier about kptr_get kfunc helpers Kumar Kartikeya Dwivedi
2022-04-09  9:33 ` [PATCH bpf-next v4 11/13] libbpf: Add kptr type tag macros to bpf_helpers.h Kumar Kartikeya Dwivedi
2022-04-09  9:33 ` [PATCH bpf-next v4 12/13] selftests/bpf: Add C tests for kptr Kumar Kartikeya Dwivedi
2022-04-09  9:33 ` [PATCH bpf-next v4 13/13] selftests/bpf: Add verifier " Kumar Kartikeya Dwivedi

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