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authorJérôme Glisse <jglisse@redhat.com>2019-04-25 22:23:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-26 09:18:05 -0700
commite153abc0739ff77bd89c9ba1688cdb963464af97 (patch)
tree87f8fcbdd0fda1970e0dffd7b1a10edfee6df158
parent89c02e69fc5245f8a2f34b58b42d43a737af1a5e (diff)
download96b-common-e153abc0739ff77bd89c9ba1688cdb963464af97.tar.gz
zram: pass down the bvec we need to read into in the work struct
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 <jglisse@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/block/zram/zram_drv.c5
1 files changed, 3 insertions, 2 deletions
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;