btrfs: fix possible memory leak in btrfs_get_dev_args_from_path()

In btrfs_get_dev_args_from_path(), btrfs_get_bdev_and_sb() can fail if
the path is invalid. In this case, btrfs_get_dev_args_from_path()
returns directly without freeing args->uuid and args->fsid allocated
before, which causes memory leak.

To fix these possible leaks, when btrfs_get_bdev_and_sb() fails,
btrfs_put_dev_args_from_path() is called to clean up the memory.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Fixes: faa775c41d655 ("btrfs: add a btrfs_get_dev_args_from_path helper")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Zixuan Fu <r33s3n6@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2729015..064ab2a 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2345,8 +2345,11 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
 
        ret = btrfs_get_bdev_and_sb(path, FMODE_READ, fs_info->bdev_holder, 0,
                                    &bdev, &disk_super);
-       if (ret)
+       if (ret) {
+               btrfs_put_dev_args_from_path(args);
                return ret;
+       }
+
        args->devid = btrfs_stack_device_id(&disk_super->dev_item);
        memcpy(args->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE);
        if (btrfs_fs_incompat(fs_info, METADATA_UUID))