From a5795fd38ee8194451ba3f281f075301a3696ce2 Mon Sep 17 00:00:00 2001 From: James Morris Date: Wed, 16 Jan 2019 15:41:11 -0800 Subject: [PATCH] LSM: Check for NULL cred-security on free From: Casey Schaufler Check that the cred security blob has been set before trying to clean it up. There is a case during credential initialization that could result in this. Signed-off-by: Casey Schaufler Acked-by: John Johansen Signed-off-by: James Morris Reported-by: syzbot+69ca07954461f189e808@syzkaller.appspotmail.com --- security/security.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/security/security.c b/security/security.c index f1b8d2587639..55bc49027ba9 100644 --- a/security/security.c +++ b/security/security.c @@ -1027,6 +1027,13 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) void security_cred_free(struct cred *cred) { + /* + * There is a failure case in prepare_creds() that + * may result in a call here with ->security being NULL. + */ + if (unlikely(cred->security == NULL)) + return; + call_void_hook(cred_free, cred); } -- 2.30.2