btrfs: fix match incorrectly in dev_args_match_device
authorLiu Shixin <liushixin2@huawei.com>
Thu, 3 Nov 2022 08:33:01 +0000 (16:33 +0800)
committerDavid Sterba <dsterba@suse.com>
Mon, 7 Nov 2022 13:30:45 +0000 (14:30 +0100)
commit0fca385d6ebc3cabb20f67bcf8a71f1448bdc001
tree18584038243e4dc1fbced7f1d327b1b91afe04a4
parenteb81b682b131642405a05c627ab08cf0967b3dd8
btrfs: fix match incorrectly in dev_args_match_device

syzkaller found a failed assertion:

  assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921

This can be triggered when we set devid to (u64)-1 by ioctl. In this
case, the match of devid will be skipped and the match of device may
succeed incorrectly.

Patch 562d7b1512f7 introduced this function which is used to match device.
This function contains two matching scenarios, we can distinguish them by
checking the value of args->missing rather than check whether args->devid
and args->uuid is default value.

Reported-by: syzbot+031687116258450f9853@syzkaller.appspotmail.com
Fixes: 562d7b1512f7 ("btrfs: handle device lookup with btrfs_dev_lookup_args")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: David Sterba <dsterba@suse.com>
fs/btrfs/volumes.c