From 7178a107f5ea7bdb1cc23073234f0ded0ef90ec7 Mon Sep 17 00:00:00 2001 From: Tianjia Zhang Date: Tue, 19 Jan 2021 00:13:19 +0000 Subject: [PATCH] X.509: Fix crash caused by NULL pointer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Tianjia Zhang Signed-off-by: David Howells Reviewed-and-tested-by: Toke Høiland-Jørgensen Tested-by: João Fonseca Acked-by: Jarkko Sakkinen Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Linus Torvalds --- 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 8892908..788a4ba 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; -- 2.7.4