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From:   Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
To:     Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>
CC:     <kasan-dev@googlegroups.com>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>, <wsd_upstream@mediatek.com>,
        <stable@vger.kernel.org>,
        Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Subject: [PATCH v2 1/1] kasan: fix memory leak of kasan quarantine
Date:   Thu, 17 Dec 2020 20:18:07 +0800
Message-ID: <1608207487-30537-2-git-send-email-Kuan-Ying.Lee@mediatek.com>
In-Reply-To: <1608207487-30537-1-git-send-email-Kuan-Ying.Lee@mediatek.com>
References: <1608207487-30537-1-git-send-email-Kuan-Ying.Lee@mediatek.com>
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Precedence: bulk

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@mediatek.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: <stable@vger.kernel.org>    [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