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bpf: Always use maximal size for copy_array()

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Instead of counting on prior allocations to have sized allocations to
the next kmalloc bucket size, always perform a krealloc that is at least
ksize(dst) in size (which is a no-op), so the size can be correctly
tracked by all the various allocation size trackers (KASAN,
__alloc_size, etc).

Reported-by: Hyunwoo Kim <v4bel@theori.io>
Link: https://lore.kernel.org/bpf/20221223094551.GA1439509@ubuntu
Fixes: ceb35b666d ("bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage")
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>
Link: https://lore.kernel.org/r/20221223182836.never.866-kees@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Kees Cook 2022-12-23 10:28:44 -08:00 committed by Alexei Starovoitov
parent f90dd663c4
commit 45435d8da7
1 changed files with 7 additions and 5 deletions
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12
kernel/bpf/verifier.c
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@ -1054,6 +1054,8 @@ static void print_insn_state(struct bpf_verifier_env *env,
*/
static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t flags)
{
size_t alloc_bytes;
void *orig = dst;
size_t bytes;
if (ZERO_OR_NULL_PTR(src))
@ -1062,11 +1064,11 @@ 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) < ksize(src)) {
kfree(dst);
dst = kmalloc_track_caller(kmalloc_size_roundup(bytes), flags);
if (!dst)
return NULL;
alloc_bytes = max(ksize(orig), kmalloc_size_roundup(bytes));
dst = krealloc(orig, alloc_bytes, flags);
if (!dst) {
kfree(orig);
return NULL;
}
memcpy(dst, src, bytes);