summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorKees Cook <keescook@chromium.org>2022-12-23 10:28:44 -0800
committerAlexei Starovoitov <ast@kernel.org>2022-12-28 14:54:53 -0800
commit45435d8da71f9f3e6860e6e6ea9667b6ec17ec64 (patch)
treead5100a0fd034d3ea7a5aeee2bac6c81cf0ee277 /kernel
parentf90dd663c492124b53bb28db6ff85b50c80ccc32 (diff)
downloadlwn-45435d8da71f9f3e6860e6e6ea9667b6ec17ec64.tar.gz
lwn-45435d8da71f9f3e6860e6e6ea9667b6ec17ec64.zip
bpf: Always use maximal size for copy_array()
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: ceb35b666d42 ("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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 243d06ce6842..85f96c1e9f62 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -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);