zram: fix race between reset and flushing pending work
authorMinchan Kim <minchan@kernel.org>
Thu, 30 Jan 2014 23:45:58 +0000 (15:45 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 31 Jan 2014 00:56:55 +0000 (16:56 -0800)
commitda4a04126baa3be03bc566d4a2ee0944c5e783d0
treefec417b4bf836105091c4f32c481442c50cabefb
parenteae70d06846199afc97524ed986b910836c0abe5
zram: fix race between reset and flushing pending work

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.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/block/zram/zram_drv.c