From: Tianjia Zhang tianjia.zhang@linux.alibaba.com
commit 7178a107f5ea7bdb1cc23073234f0ded0ef90ec7 upstream.
On the following call path, `sig->pkey_algo` is not assigned in asymmetric_key_verify_signature(), which causes runtime crash in public_key_verify_signature().
keyctl_pkey_verify asymmetric_key_verify_signature verify_signature public_key_verify_signature
This patch simply check this situation and fixes the crash caused by NULL pointer.
Fixes: 215525639631 ("X.509: support OSCCA SM2-with-SM3 certificate verification") Reported-by: Tobias Markus tobias@markus-regensburg.de Signed-off-by: Tianjia Zhang tianjia.zhang@linux.alibaba.com Signed-off-by: David Howells dhowells@redhat.com Reviewed-and-tested-by: Toke Høiland-Jørgensen toke@redhat.com Tested-by: João Fonseca jpedrofonseca@ua.pt Acked-by: Jarkko Sakkinen jarkko@kernel.org Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/asymmetric_keys/public_key.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -356,7 +356,8 @@ int public_key_verify_signature(const st if (ret) goto error_free_key;
- if (strcmp(sig->pkey_algo, "sm2") == 0 && sig->data_size) { + if (sig->pkey_algo && strcmp(sig->pkey_algo, "sm2") == 0 && + sig->data_size) { ret = cert_sig_digest_update(sig, tfm); if (ret) goto error_free_key;