[PATCH 2/2] AppArmor: Fix lsm_get_self_attr()

[Mickaël Salaün]

aa_getprocattr() may not initialize the value's pointer in some case.
As for proc_pid_attr_read(), initialize this pointer to NULL in
apparmor_getselfattr() to avoid an UAF in the kfree() call.

Cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Cc: John Johansen <john.johansen@xxxxxxxxxxxxx>
Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 223981db9baf ("AppArmor: Add selfattr hooks")
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
---
 security/apparmor/lsm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 98e1150bee9d..9a3dcaafb5b1 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -784,7 +784,7 @@ static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
 	int error = -ENOENT;
 	struct aa_task_ctx *ctx = task_ctx(current);
 	struct aa_label *label = NULL;
-	char *value;
+	char *value = NULL;
 
 	switch (attr) {
 	case LSM_ATTR_CURRENT:
-- 
2.43.0