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authorDavid Sterba <dsterba@suse.cz>2013-04-26 15:20:23 +0000
committerJosef Bacik <jbacik@fusionio.com>2013-05-06 15:55:25 -0400
commit55793c0d0381176e727389325d9a47f7f0b5387f (patch)
tree580c9b7f5562e314bf13a8cdb92b342bc17db75a
parentf7a52a40cabea38b99b5053bc4f7cf45f4997603 (diff)
downloadlinaro-lsk-55793c0d0381176e727389325d9a47f7f0b5387f.tar.gz
btrfs: read entire device info under lock
There's a theoretical possibility of reading stale (or even more theoretically, freed) data from DEV_INFO ioctl when the device would disappear between an early mutex unlock and data being copied from the device structure. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
-rw-r--r--fs/btrfs/ioctl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3aa37508bf2..0de4a2fcfb2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2432,7 +2432,6 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
mutex_lock(&fs_devices->device_list_mutex);
dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
- mutex_unlock(&fs_devices->device_list_mutex);
if (!dev) {
ret = -ENODEV;
@@ -2456,6 +2455,7 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
}
out:
+ mutex_unlock(&fs_devices->device_list_mutex);
if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
ret = -EFAULT;