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authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2016-07-14 12:07:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-15 14:54:27 +0900
commit0ab686d8c8303069e80300663b3be6201a8697fb (patch)
tree6dbd0663ea51debd295f0d24b656c82fdfc29497 /mm/kasan
parent12cb22bb8ae9aff9d72a9c0a234f26d641b20eb6 (diff)
downloadlinux-0ab686d8c8303069e80300663b3be6201a8697fb.tar.bz2
kasan/quarantine: fix bugs on qlist_move_cache()
There are two bugs on qlist_move_cache(). One is that qlist's tail isn't set properly. curr->next can be NULL since it is singly linked list and NULL value on tail is invalid if there is one item on qlist. Another one is that if cache is matched, qlist_put() is called and it will set curr->next to NULL. It would cause to stop the loop prematurely. These problems come from complicated implementation so I'd like to re-implement it completely. Implementation in this patch is really simple. Iterate all qlist_nodes and put them to appropriate list. Unfortunately, I got this bug sometime ago and lose oops message. But, the bug looks trivial and no need to attach oops. Fixes: 55834c59098d ("mm: kasan: initial memory quarantine implementation") Link: http://lkml.kernel.org/r/1467766348-22419-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Kuthonuzo Luruo <poll.stdin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
-rw-r--r--mm/kasan/quarantine.c29
1 files changed, 11 insertions, 18 deletions
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 4973505a9bdd..65793f150d1f 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -238,30 +238,23 @@ static void qlist_move_cache(struct qlist_head *from,
struct qlist_head *to,
struct kmem_cache *cache)
{
- struct qlist_node *prev = NULL, *curr;
+ struct qlist_node *curr;
if (unlikely(qlist_empty(from)))
return;
curr = from->head;
+ qlist_init(from);
while (curr) {
- struct qlist_node *qlink = curr;
- struct kmem_cache *obj_cache = qlink_to_cache(qlink);
-
- if (obj_cache == cache) {
- if (unlikely(from->head == qlink)) {
- from->head = curr->next;
- prev = curr;
- } else
- prev->next = curr->next;
- if (unlikely(from->tail == qlink))
- from->tail = curr->next;
- from->bytes -= cache->size;
- qlist_put(to, qlink, cache->size);
- } else {
- prev = curr;
- }
- curr = curr->next;
+ struct qlist_node *next = curr->next;
+ struct kmem_cache *obj_cache = qlink_to_cache(curr);
+
+ if (obj_cache == cache)
+ qlist_put(to, curr, obj_cache->size);
+ else
+ qlist_put(from, curr, obj_cache->size);
+
+ curr = next;
}
}