diff options
| author | Jan Kara <jack@suse.cz> | 2017-03-08 17:48:33 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-03-08 18:55:17 +0100 |
| commit | 90f16fddcc2802726142b8386c65ccb89f044613 (patch) | |
| tree | da1c8d56ab62dd362dc94fab542ba43a5144f67d | |
| parent | bdi: Fix use-after-free in wb_congested_put() (diff) | |
| download | linux-90f16fddcc2802726142b8386c65ccb89f044613.tar.xz linux-90f16fddcc2802726142b8386c65ccb89f044613.zip | |
block: Make del_gendisk() safer for disks without queues
Commit 165a5e22fafb "block: Move bdi_unregister() to del_gendisk()"
added disk->queue dereference to del_gendisk(). Although del_gendisk()
is not supposed to be called without disk->queue valid and
blk_unregister_queue() warns in that case, this change will make it oops
instead. Return to the old more robust behavior of just warning when
del_gendisk() gets called for gendisk with disk->queue being NULL.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/genhd.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/block/genhd.c b/block/genhd.c index b26a5ea115d0..94f323842b52 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -681,12 +681,16 @@ void del_gendisk(struct gendisk *disk) disk->flags &= ~GENHD_FL_UP; sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); - /* - * Unregister bdi before releasing device numbers (as they can get - * reused and we'd get clashes in sysfs). - */ - bdi_unregister(disk->queue->backing_dev_info); - blk_unregister_queue(disk); + if (disk->queue) { + /* + * Unregister bdi before releasing device numbers (as they can + * get reused and we'd get clashes in sysfs). + */ + bdi_unregister(disk->queue->backing_dev_info); + blk_unregister_queue(disk); + } else { + WARN_ON(1); + } blk_unregister_region(disk_devt(disk), disk->minors); part_stat_set_all(&disk->part0, 0); |