From: Kees Cook <keescook@chromium.org>
To: Alexei Starovoitov <ast@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>,
bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH bpf-next v2 2/3] bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage
Date: Fri, 28 Oct 2022 19:54:31 -0700 [thread overview]
Message-ID: <20221029025433.2533810-2-keescook@chromium.org> (raw)
In-Reply-To: <20221029024444.gonna.633-kees@kernel.org>
Round up allocations with kmalloc_size_roundup() so that the verifier's
use of ksize() is always accurate and no special handling of the memory
is needed by KASAN, UBSAN_BOUNDS, nor FORTIFY_SOURCE. Pass the new size
information back up to callers so they can use the space immediately,
so array resizing to happen less frequently as well.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: bpf@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
kernel/bpf/verifier.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index eb8c34db74c7..1c040d27b8f6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1008,9 +1008,9 @@ static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t
if (unlikely(check_mul_overflow(n, size, &bytes)))
return NULL;
- if (ksize(dst) < bytes) {
+ if (ksize(dst) < ksize(src)) {
kfree(dst);
- dst = kmalloc_track_caller(bytes, flags);
+ dst = kmalloc_track_caller(kmalloc_size_roundup(bytes), flags);
if (!dst)
return NULL;
}
@@ -1027,12 +1027,14 @@ static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t
*/
static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t size)
{
+ size_t alloc_size;
void *new_arr;
if (!new_n || old_n == new_n)
goto out;
- new_arr = krealloc_array(arr, new_n, size, GFP_KERNEL);
+ alloc_size = kmalloc_size_roundup(size_mul(new_n, size));
+ new_arr = krealloc(arr, alloc_size, GFP_KERNEL);
if (!new_arr) {
kfree(arr);
return NULL;
@@ -2504,9 +2506,11 @@ static int push_jmp_history(struct bpf_verifier_env *env,
{
u32 cnt = cur->jmp_history_cnt;
struct bpf_idx_pair *p;
+ size_t alloc_size;
cnt++;
- p = krealloc(cur->jmp_history, cnt * sizeof(*p), GFP_USER);
+ alloc_size = kmalloc_size_roundup(size_mul(cnt, sizeof(*p)));
+ p = krealloc(cur->jmp_history, alloc_size, GFP_USER);
if (!p)
return -ENOMEM;
p[cnt - 1].idx = env->insn_idx;
--
2.34.1
next prev parent reply other threads:[~2022-10-29 2:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-29 2:54 [PATCH bpf-next v2 0/3] bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage Kees Cook
2022-10-29 2:54 ` [PATCH bpf-next v2 1/3] bpf/verifier: Fix potential memory leak in array reallocation Kees Cook
2022-10-31 20:16 ` Bill Wendling
2022-11-01 13:46 ` Daniel Borkmann
2022-11-15 16:07 ` Lorenz Bauer
2022-10-29 2:54 ` Kees Cook [this message]
2022-11-01 13:52 ` [PATCH bpf-next v2 2/3] bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage Daniel Borkmann
2022-11-01 17:01 ` Kees Cook
2022-10-29 2:54 ` [PATCH bpf-next v2 3/3] bpf/verifier: Take advantage of full allocation sizes Kees Cook
2022-10-31 21:53 ` Stanislav Fomichev
2022-11-01 5:23 ` Kees Cook
2022-11-01 13:40 ` [PATCH bpf-next v2 0/3] bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage patchwork-bot+netdevbpf
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