diff options
| author |   Ilya Dryomov <idryomov@gmail.com> | 2013-10-02 20:41:01 +0300 |
|---|---|---|
| committer |   Josef Bacik <jbacik@fusionio.com> | 2013-10-04 16:02:14 -0400 |
| commit | 1357272fc7deeebb7b3c5d1a071562edc273cdaf (patch) | |
| tree | 37af6be54b03e07b4fb06a2ddc4c5ac739c53032 /fs/btrfs/volumes.c | |
| parent | Btrfs: eliminate races in worker stopping code (diff) | |
| download | linux-dev-1357272fc7deeebb7b3c5d1a071562edc273cdaf.tar.xz linux-dev-1357272fc7deeebb7b3c5d1a071562edc273cdaf.zip | |
Btrfs: fix a use-after-free bug in btrfs_dev_replace_finishing
free_device rcu callback, scheduled from btrfs_rm_dev_replace_srcdev,
can be processed before btrfs_scratch_superblock is called, which would
result in a use-after-free on btrfs_device contents. Fix this by
zeroing the superblock before the rcu callback is registered.
Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/volumes.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 043114749516..b0203b1322ac 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1716,6 +1716,7 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info, struct btrfs_device *srcdev) { WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex)); + list_del_rcu(&srcdev->dev_list); list_del_rcu(&srcdev->dev_alloc_list); fs_info->fs_devices->num_devices--; @@ -1725,9 +1726,13 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info, } if (srcdev->can_discard) fs_info->fs_devices->num_can_discard--; - if (srcdev->bdev) + if (srcdev->bdev) { fs_info->fs_devices->open_devices--; + /* zero out the old super */ + btrfs_scratch_superblock(srcdev); + } + call_rcu(&srcdev->rcu, free_device); } |