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| author | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-23 21:02:09 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-03 10:09:21 +0200 |
| commit | 9dd6f6d89693d8f09af53d2488afad22a8a44a57 (patch) | |
| tree | b141555f419f1ee6ceb39139a3a1178a1a7e8e93 /kernel | |
| parent | ad41706c771a038e9a334fa55216abd69b32bfdf (diff) | |
| download | linux-stable-9dd6f6d89693d8f09af53d2488afad22a8a44a57.tar.gz linux-stable-9dd6f6d89693d8f09af53d2488afad22a8a44a57.tar.bz2 linux-stable-9dd6f6d89693d8f09af53d2488afad22a8a44a57.zip | |
bpf: Fix ringbuf helper function compatibility
commit 5b029a32cfe4600f5e10e36b41778506b90fd4de upstream.
Commit 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support
for it") extended check_map_func_compatibility() by enforcing map -> helper
function match, but not helper -> map type match.
Due to this all of the bpf_ringbuf_*() helper functions could be used with
a wrong map type such as array or hash map, leading to invalid access due
to type confusion.
Also, both BPF_FUNC_ringbuf_{submit,discard} have ARG_PTR_TO_ALLOC_MEM as
argument and not a BPF map. Therefore, their check_map_func_compatibility()
presence is incorrect since it's only for map type checking.
Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Ryota Shiga (Flatt Security)
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1410f128c404..29d4f4e37595 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4693,8 +4693,6 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_MAP_TYPE_RINGBUF: if (func_id != BPF_FUNC_ringbuf_output && func_id != BPF_FUNC_ringbuf_reserve && - func_id != BPF_FUNC_ringbuf_submit && - func_id != BPF_FUNC_ringbuf_discard && func_id != BPF_FUNC_ringbuf_query) goto error; break; @@ -4798,6 +4796,12 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) goto error; break; + case BPF_FUNC_ringbuf_output: + case BPF_FUNC_ringbuf_reserve: + case BPF_FUNC_ringbuf_query: + if (map->map_type != BPF_MAP_TYPE_RINGBUF) + goto error; + break; case BPF_FUNC_get_stackid: if (map->map_type != BPF_MAP_TYPE_STACK_TRACE) goto error; |