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| 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/dev-replace.c | |
| parent | 964fb15acfcd672ac691f04879b71f07ccc21e0c (diff) | |
| download | lwn-1357272fc7deeebb7b3c5d1a071562edc273cdaf.tar.gz lwn-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 'fs/btrfs/dev-replace.c')
| -rw-r--r-- | fs/btrfs/dev-replace.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 5d844438b2d4..2a9bd5bd24c3 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -535,10 +535,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); btrfs_rm_dev_replace_srcdev(fs_info, src_device); - if (src_device->bdev) { - /* zero out the old super */ - btrfs_scratch_superblock(src_device); - } + /* * this is again a consistent state where no dev_replace procedure * is running, the target device is part of the filesystem, the |