From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Minchan Kim To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Nitin Gupta , Jerome Marchand , Sergey Senozhatsky , Minchan Kim , stable Subject: [PATCH 1/7] zram: fix race between reset and flushing pending work Date: Mon, 13 Jan 2014 20:18:56 +0900 Message-Id: <1389611942-15544-2-git-send-email-minchan@kernel.org> In-Reply-To: <1389611942-15544-1-git-send-email-minchan@kernel.org> References: <1389611942-15544-1-git-send-email-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Dan and Sergey reported that there is a racy between reset and flushing of pending work so that it could make oops by freeing zram->meta in reset while zram_slot_free can access zram->meta if new request is adding during the race window. This patch moves flush after taking init_lock so it prevents new request so that it closes the race. Cc: stable Signed-off-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index f9711c5..213dfc1 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -553,14 +553,14 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) size_t index; struct zram_meta *meta; - flush_work(&zram->free_work); - down_write(&zram->init_lock); if (!zram->init_done) { up_write(&zram->init_lock); return; } + flush_work(&zram->free_work); + meta = zram->meta; zram->init_done = 0; -- 1.8.4.3