diff options
| author | Ming Lei <ming.lei@redhat.com> | 2020-12-21 12:33:35 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-17 13:55:14 +0100 |
| commit | a09652089d496a4ecb925e2cb95a6523f22ae538 (patch) | |
| tree | 0ca909bfb5aeeadc09c61482146a41777ad7796f | |
| parent | d5453054e2da78cfaf1ec9d18e906702db852b2c (diff) | |
block: fix use-after-free in disk_part_iter_next
commit aebf5db917055b38f4945ed6d621d9f07a44ff30 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | block/genhd.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/block/genhd.c b/block/genhd.c index 3032453a89e6..0b8c65e51adf 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -158,14 +158,17 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; + get_device(part_to_dev(part)); + piter->part = part; if (!part_nr_sects_read(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && - piter->idx == 0)) + piter->idx == 0)) { + put_device(part_to_dev(part)); + piter->part = NULL; continue; + } - get_device(part_to_dev(part)); - piter->part = part; piter->idx += inc; break; } |