This is a note to let you know that I've just added the patch titled
X.509: if signature is unsupported skip validation
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x.509-if-signature-is-unsupported-skip-validation.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ef5b52a631f8c18353e80ccab8408b963305510c Mon Sep 17 00:00:00 2001
From: Thore Sommer <public@xxxxxxxx>
Date: Tue, 15 Aug 2023 14:29:42 +0300
Subject: X.509: if signature is unsupported skip validation
From: Thore Sommer <public@xxxxxxxx>
commit ef5b52a631f8c18353e80ccab8408b963305510c upstream.
When the hash algorithm for the signature is not available the digest size
is 0 and the signature in the certificate is marked as unsupported.
When validating a self-signed certificate, this needs to be checked,
because otherwise trying to validate the signature will fail with an
warning:
Loading compiled-in X.509 certificates
WARNING: CPU: 0 PID: 1 at crypto/rsa-pkcs1pad.c:537 \
pkcs1pad_verify+0x46/0x12c
...
Problem loading in-kernel X.509 certificate (-22)
Signed-off-by: Thore Sommer <public@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.7+
Fixes: 6c2dc5ae4ab7 ("X.509: Extract signature digest and make self-signed cert checks earlier")
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/asymmetric_keys/x509_public_key.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -134,6 +134,11 @@ int x509_check_for_self_signed(struct x5
if (strcmp(cert->pub->pkey_algo, cert->sig->pkey_algo) != 0)
goto out;
+ if (cert->unsupported_sig) {
+ ret = 0;
+ goto out;
+ }
+
ret = public_key_verify_signature(cert->pub, cert->sig);
if (ret < 0) {
if (ret == -ENOPKG) {
Patches currently in stable-queue which might be from public@xxxxxxxx are
queue-4.19/x.509-if-signature-is-unsupported-skip-validation.patch
