From: Catalin Marinas <catalin.marinas@arm.com>
Date: Wed, 27 Apr 2011 15:44:26 +0000 (+0100)
Subject: kmemleak: Do not return a pointer to an object that kmemleak did not get
X-Git-Tag: v2.6.32.42~90
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b2300b3b5d1294dcdb655ee34800ba8b3cfdc65d;p=karo-tx-linux.git

kmemleak: Do not return a pointer to an object that kmemleak did not get

commit 52c3ce4ec5601ee383a14f1485f6bac7b278896e upstream.

The kmemleak_seq_next() function tries to get an object (and increment
its use count) before returning it. If it could not get the last object
during list traversal (because it may have been freed), the function
should return NULL rather than a pointer to such object that it did not
get.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 8bf765c4f58d..c3466601d3e7 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1354,9 +1354,12 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	++(*pos);
 
 	list_for_each_continue_rcu(n, &object_list) {
-		next_obj = list_entry(n, struct kmemleak_object, object_list);
-		if (get_object(next_obj))
+		struct kmemleak_object *obj =
+			list_entry(n, struct kmemleak_object, object_list);
+		if (get_object(obj)) {
+			next_obj = obj;
 			break;
+		}
 	}
 
 	put_object(prev_obj);