KEYS: prevent NULL pointer dereference in find_asymmetric_key()

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: 7d30198ee2 ("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>
This commit is contained in:
Roman Smirnov 2024-09-17 18:54:53 +03:00 committed by Jarkko Sakkinen
parent 652bfcb76f
commit 70fd1966c9

View File

@ -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>". */