diff options
| author | KP Singh <kpsingh@kernel.org> | 2026-05-20 04:40:59 +0200 |
|---|---|---|
| committer | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-05-20 05:12:05 +0200 |
| commit | 49b18315be4eecfc36b75f4aecb4d40a87d68a20 (patch) | |
| tree | e4ef3d8bf07a51dae94329119e295fad42e142d1 | |
| parent | 201166d79fc01b607eccdddd4e1a7189f231904b (diff) | |
bpf: Reject NULL data/sig in bpf_verify_pkcs7_signature
__bpf_dynptr_data() can return NULL (FILE dynptrs, any non-contiguous
backing). bpf_verify_pkcs7_signature() forwards the pointer to
verify_pkcs7_signature() unchecked, causing a NULL deref in
asn1_ber_decoder() reachable from a sleepable BPF LSM at lsm.s/bpf.
NULL-check both pointers and reject with -EINVAL. Mirrors the guards
already in kernel/bpf/crypto.c.
Fixes: 865b0566d8f1 ("bpf: Add bpf_verify_pkcs7_signature() kfunc")
Reported-by: Xianrui Dong <dongxianrui1@gmail.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260520024059.313468-1-kpsingh@kernel.org
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
| -rw-r--r-- | kernel/bpf/helpers.c | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 2bb60200c266..b5314c9fed3c 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -4241,8 +4241,13 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, data_len = __bpf_dynptr_size(data_ptr); data = __bpf_dynptr_data(data_ptr, data_len); + if (!data) + return -EINVAL; + sig_len = __bpf_dynptr_size(sig_ptr); sig = __bpf_dynptr_data(sig_ptr, sig_len); + if (!sig) + return -EINVAL; return verify_pkcs7_signature(data, data_len, sig, sig_len, trusted_keyring->key, diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c index 8cd298b78e44..04aaf4c9cf5e 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c @@ -14,7 +14,7 @@ static struct { const char *prog_name; int expected_runtime_err; } kfunc_dynptr_tests[] = { - {"dynptr_data_null", -EBADMSG}, + {"dynptr_data_null", -EINVAL}, }; static bool kfunc_not_supported; |