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authorSasha Levin <sasha.levin@oracle.com>2015-05-12 19:31:37 -0400
committerChris Mason <clm@fb.com>2015-06-02 19:34:36 -0700
commit2037a0933bc2894a2f50ae57a1ccf6be192adb76 (patch)
tree717aee3ea647947a67f0b9afa83ccb161398eb30
parent01b810b889d557257580970e1a7ba9c85b54766b (diff)
btrfs: use after free when closing devices
__btrfs_close_devices() would call_rcu to free the device, which is racy with list_for_each_entry() accessing the memory to retrieve the next device on the list. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
-rw-r--r--fs/btrfs/volumes.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 403ed1fdd901..c99f29a52e0b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -693,13 +693,13 @@ static void free_device(struct rcu_head *head)
static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
- struct btrfs_device *device;
+ struct btrfs_device *device, *tmp;
if (--fs_devices->opened > 0)
return 0;
mutex_lock(&fs_devices->device_list_mutex);
- list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
struct btrfs_device *new_device;
struct rcu_string *name;