[PATCH v2 1/1] kasan: fix memory leak of kasan quarantine

[Kuan-Ying Lee]

When cpu is going offline, set q->offline as true
and interrupt happened. The interrupt may call the
quarantine_put. But quarantine_put do not free the
the object. The object will cause memory leak.

Add qlink_free() to free the object.

Fixes: 6c82d45c7f03 (kasan: fix object remaining in offline per-cpu quarantine)
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>    [5.10-]
---
 mm/kasan/quarantine.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 0e3f8494628f..cac7c617df72 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -191,6 +191,7 @@ void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache)
 
 	q = this_cpu_ptr(&cpu_quarantine);
 	if (q->offline) {
+		qlink_free(&info->quarantine_link, cache);
 		local_irq_restore(flags);
 		return;
 	}
-- 
2.18.0