From 70fd1966c93bf3bfe3fe6d753eb3d83a76597eef Mon Sep 17 00:00:00 2001 From: Roman Smirnov Date: Tue, 17 Sep 2024 18:54:53 +0300 Subject: [PATCH] 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: 7d30198ee24f ("keys: X.509 public key issuer lookup without AKID") Suggested-by: Sergey Shtylyov Signed-off-by: Roman Smirnov Reviewed-by: Sergey Shtylyov Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- crypto/asymmetric_keys/asymmetric_type.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index a5da8ccd353e..43af5fa510c0 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -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:". */