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| author | Liu Bo <bo.li.liu@oracle.com> | 2013-05-26 17:50:27 +0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@fusionio.com> | 2013-06-08 23:10:01 +0400 |
| commit | 2932505abe7c56477315a3d93ffb3c27c5182e9d (patch) | |
| tree | 87fadf5f979b36cdcad79a5d4f4c6cd587b68422 /fs | |
| parent | a9995eece39a0630ebbfc1ab38570bce6c8a8f5b (diff) | |
| download | linux-2932505abe7c56477315a3d93ffb3c27c5182e9d.tar.xz | |
Btrfs: fix use-after-free bug during umount
Commit be283b2e674a09457d4563729015adb637ce7cc1
( Btrfs: use helper to cleanup tree roots) introduced the following bug,
BUG: unable to handle kernel NULL pointer dereference at 0000000000000034
IP: [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
[...]
Pid: 2463, comm: btrfs-cache-1 Tainted: G O 3.9.0+ #4 innotek GmbH VirtualBox/VirtualBox
RIP: 0010:[<ffffffffa039368c>] [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
Process btrfs-cache-1 (pid: 2463, threadinfo ffff880112d60000, task ffff880117679730)
[...]
Call Trace:
[<ffffffffa0398a99>] btrfs_search_slot+0x104/0x64d [btrfs]
[<ffffffffa039aea4>] btrfs_next_old_leaf+0xa7/0x334 [btrfs]
[<ffffffffa039b141>] btrfs_next_leaf+0x10/0x12 [btrfs]
[<ffffffffa039ea13>] caching_thread+0x1a3/0x2e0 [btrfs]
[<ffffffffa03d8811>] worker_loop+0x14b/0x48e [btrfs]
[<ffffffffa03d86c6>] ? btrfs_queue_worker+0x25c/0x25c [btrfs]
[<ffffffff81068d3d>] kthread+0x8d/0x95
[<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43
[<ffffffff8151e5ac>] ret_from_fork+0x7c/0xb0
[<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43
RIP [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
We've free'ed commit_root before actually getting to free block groups where
caching thread needs valid extent_root->commit_root.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index bdaa092d6296..7c66c2314c14 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3512,10 +3512,10 @@ int close_ctree(struct btrfs_root *root) percpu_counter_sum(&fs_info->delalloc_bytes)); } - free_root_pointers(fs_info, 1); - btrfs_free_block_groups(fs_info); + free_root_pointers(fs_info, 1); + del_fs_roots(fs_info); iput(fs_info->btree_inode); |