From: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Reviewed-and-tested-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> --- crypto/asymmetric_keys/public_key.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 8892908ad58c..788a4ba1e2e7 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -356,7 +356,8 @@ int public_key_verify_signature(const struct public_key *pkey, 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;