From e153abc0739ff77bd89c9ba1688cdb963464af97 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Date: Thu, 25 Apr 2019 22:23:41 -0700 Subject: zram: pass down the bvec we need to read into in the work struct MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When scheduling work item to read page we need to pass down the proper bvec struct which points to the page to read into. Before this patch it uses a randomly initialized bvec (only if PAGE_SIZE != 4096) which is wrong. Note that without this patch on arch/kernel where PAGE_SIZE != 4096 userspace could read random memory through a zram block device (thought userspace probably would have no control on the address being read). Link: http://lkml.kernel.org/r/20190408183219.26377-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse Reviewed-by: Andrew Morton Reviewed-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Nitin Gupta Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 399cad7daae7..d58a359a6622 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -774,18 +774,18 @@ struct zram_work { struct zram *zram; unsigned long entry; struct bio *bio; + struct bio_vec bvec; }; #if PAGE_SIZE != 4096 static void zram_sync_read(struct work_struct *work) { - struct bio_vec bvec; struct zram_work *zw = container_of(work, struct zram_work, work); struct zram *zram = zw->zram; unsigned long entry = zw->entry; struct bio *bio = zw->bio; - read_from_bdev_async(zram, &bvec, entry, bio); + read_from_bdev_async(zram, &zw->bvec, entry, bio); } /* @@ -798,6 +798,7 @@ static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec, { struct zram_work work; + work.bvec = *bvec; work.zram = zram; work.entry = entry; work.bio = bio; -- cgit v1.2.3