Hi,

I have fixed this problem last week. Still thanks for your fixing. patch is here: https://lkml.org/lkml/2021/1/7/201

Best regards, Tianjia

On 1/13/21 12:10 AM, Toke Høiland-Jørgensen wrote:

When public_key_verify_signature() is called from asymmetric_key_verify_signature(), the pkey_algo field of struct public_key_signature will be NULL, which causes a NULL pointer dereference in the strcmp() check. Fix this by adding a NULL check.

One visible manifestation of this is that userspace programs (such as the 'iwd' WiFi daemon) will be killed when trying to verify a TLS key using the keyctl(2) interface.

Cc: stable@vger.kernel.org Fixes: 215525639631 ("X.509: support OSCCA SM2-with-SM3 certificate verification") Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com

---

crypto/asymmetric_keys/public_key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 8892908ad58c..35b09e95a870 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -356,7 +356,7 @@ 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;

I'm intending to use Tianjia's patch. Would you like to add a Reviewed-by?

David --- commit 11078a592e6dcea6b9f30e822d3d30e3defc99ca Author: Tianjia Zhang tianjia.zhang@linux.alibaba.com Date: Thu Jan 7 17:28:55 2021 +0800

X.509: Fix crash caused by NULL pointer

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") Cc: stable@vger.kernel.org # v5.10+ 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

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;