Commit a372c4c5 authored Oct 28, 2024 by Roman Smirnov Committed by Yi Yang Oct 28, 2024

KEYS: prevent NULL pointer dereference in find_asymmetric_key()

stable inclusion
from stable-v6.6.54
commit a3765b497a4f5224cb2f7a6a2d3357d3066214ee
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYR0Z
CVE: CVE-2024-47743

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a3765b497a4f5224cb2f7a6a2d3357d3066214ee



--------------------------------

commit 70fd1966c93bf3bfe3fe6d753eb3d83a76597eef upstream.

In find_asymmetric_key(), if all NULLs are passed in the id_{0,1,2}
arguments, the kernel will first emit WARN but then have an oops
because id_2 gets dereferenced anyway.

Add the missing id_2 check and move WARN_ON() to the final else branch
to avoid duplicate NULL checks.

Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.

Cc: stable@vger.kernel.org # v5.17+
Fixes: 7d30198e ("keys: X.509 public key issuer lookup without AKID")
Suggested-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yi Yang <yiyang13@huawei.com>

parent 9d0af12b

crypto/asymmetric_keys/asymmetric_type.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -60,17 +60,18 @@ struct key find_asymmetric_key(struct key keyring,
		char req, p;
		int len;

		WARN_ON(!id_0 && !id_1 && !id_2);

		if (id_0) {
		lookup = id_0->data;
		len = id_0->len;
		} else if (id_1) {
		lookup = id_1->data;
		len = id_1->len;
		} else {
		} else if (id_2) {
		lookup = id_2->data;
		len = id_2->len;
		} else {
		WARN_ON(1);
		return ERR_PTR(-EINVAL);
		}

		/* Construct an identifier "id:<keyid>". */