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| author | Miao Xie <miaox@cn.fujitsu.com> | 2014-09-03 15:35:43 +0200 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-09-17 22:38:44 +0200 |
| commit | 67a2c45ee7f4f250458279a2e1244679c5d9735c (patch) | |
| tree | 0f1806d2aead6af9629bb701101b75b28863b986 /fs/btrfs/locking.c | |
| parent | Btrfs: fix unprotected device list access when cloning fs devices (diff) | |
| download | linux-67a2c45ee7f4f250458279a2e1244679c5d9735c.tar.xz linux-67a2c45ee7f4f250458279a2e1244679c5d9735c.zip | |
Btrfs: fix use-after-free problem of the device during device replace
The problem is:
Task0(device scan task) Task1(device replace task)
scan_one_device()
mutex_lock(&uuid_mutex)
device = find_device()
mutex_lock(&device_list_mutex)
lock_chunk()
rm_and_free_source_device
unlock_chunk()
mutex_unlock(&device_list_mutex)
check device
Destroying the target device if device replace fails also has the same problem.
We fix this problem by locking uuid_mutex during destroying source device or
target device, just like the device remove operation.
It is a temporary solution, we can fix this problem and make the code more
clear by atomic counter in the future.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/locking.c')
0 files changed, 0 insertions, 0 deletions