diff options
| author | Ming Lei <ming.lei@redhat.com> | 2020-12-21 05:33:35 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-05 19:35:17 +0100 |
| commit | aebf5db917055b38f4945ed6d621d9f07a44ff30 (patch) | |
| tree | cbe567d6e39da630210e8b9284cfaed3db72aa91 | |
| parent | bfq: Fix computation of shallow depth (diff) | |
| download | linux-aebf5db917055b38f4945ed6d621d9f07a44ff30.tar.xz linux-aebf5db917055b38f4945ed6d621d9f07a44ff30.zip | |
block: fix use-after-free in disk_part_iter_next
Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.
Cc: <stable@vger.kernel.org>
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/genhd.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/block/genhd.c b/block/genhd.c index 73faec438e49..419548e92d82 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -246,15 +246,18 @@ struct block_device *disk_part_iter_next(struct disk_part_iter *piter) part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; + piter->part = bdgrab(part); + if (!piter->part) + continue; if (!bdev_nr_sectors(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && - piter->idx == 0)) + piter->idx == 0)) { + bdput(piter->part); + piter->part = NULL; continue; + } - piter->part = bdgrab(part); - if (!piter->part) - continue; piter->idx += inc; break; } |