Commit 70fd1966 authored by Roman Smirnov's avatar Roman Smirnov Committed by Jarkko Sakkinen
Browse files

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: 7d30198e ("keys: X.509 public key issuer lookup without AKID")
Suggested-by: default avatarSergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: default avatarRoman Smirnov <r.smirnov@omp.ru>
Reviewed-by: default avatarSergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 652bfcb7

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>". */