From: Tianjia Zhang <tianjia.zh...@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 <tob...@markus-regensburg.de> Signed-off-by: Tianjia Zhang <tianjia.zh...@linux.alibaba.com> Signed-off-by: David Howells <dhowe...@redhat.com> Reviewed-and-tested-by: Toke Høiland-Jørgensen <t...@redhat.com> Tested-by: João Fonseca <jpedrofons...@ua.pt> Acked-by: Jarkko Sakkinen <jar...@kernel.org> Cc: sta...@vger.kernel.org # v5.10+ Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@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;