From: Daniel Borkmann daniel@iogearbox.net
mainline inclusion from mainline-5.10.62 commit 9dd6f6d89693d8f09af53d2488afad22a8a44a57 bugzilla: 182217 https://gitee.com/openeuler/kernel/issues/I4EFOS
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- kernel/bpf/verifier.c | 8 ++++++-- 1 file 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;