From: Christoph Hellwig hch@lst.de
[ Upstream commit 99d8690aae4b2f0d1d90075de355ac087f820a66 ]
One device_add is called disk->ev will be freed by disk_release, so we should free it twice. Fix this by allocating disk->ev after device_add so that the extra local unwinding can be removed entirely.
Based on an earlier patch from Tetsuo Handa.
Reported-by: syzbot syzbot+28a66a9fbc621c939000@syzkaller.appspotmail.com Tested-by: syzbot syzbot+28a66a9fbc621c939000@syzkaller.appspotmail.com Fixes: 83cbce9574462c6b ("block: add error handling for device_add_disk / add_disk") Signed-off-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20211221161851.788424-1-hch@lst.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/genhd.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c index f091a60dcf1ea..22f899615801c 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -432,10 +432,6 @@ int device_add_disk(struct device *parent, struct gendisk *disk, disk->flags |= GENHD_FL_EXT_DEVT; }
- ret = disk_alloc_events(disk); - if (ret) - goto out_free_ext_minor; - /* delay uevents, until we scanned partition table */ dev_set_uevent_suppress(ddev, 1);
@@ -446,7 +442,12 @@ int device_add_disk(struct device *parent, struct gendisk *disk, ddev->devt = MKDEV(disk->major, disk->first_minor); ret = device_add(ddev); if (ret) - goto out_disk_release_events; + goto out_free_ext_minor; + + ret = disk_alloc_events(disk); + if (ret) + goto out_device_del; + if (!sysfs_deprecated) { ret = sysfs_create_link(block_depr, &ddev->kobj, kobject_name(&ddev->kobj)); @@ -534,8 +535,6 @@ out_del_block_link: sysfs_remove_link(block_depr, dev_name(ddev)); out_device_del: device_del(ddev); -out_disk_release_events: - disk_release_events(disk); out_free_ext_minor: if (disk->major == BLOCK_EXT_MAJOR) blk_free_ext_minor(disk->first_minor);