[PATCH 1/2] LSM: Check for NULL cred-security on free

[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 <casey@xxxxxxxxxxxxxxxx>
---
 security/security.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/security/security.c b/security/security.c
index a618e22df5c6..7bffc86d4e87 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1477,6 +1477,13 @@ 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);
 
 	kfree(cred->security);
-- 
2.20.1