[PATCH 4.19 055/105] btrfs: free btrfs_path before copying subvol info to userspace

Greg Kroah-Hartman
2022-12-05T19:20:16Z

From: Anand Jain <anand.jain@oracle.com>

commit 013c1c5585ebcfb19c88efe79063d0463b1b6159 upstream.

btrfs_ioctl_get_subvol_info() frees the search path after the userspace
copy from the temp buffer @subvol_info. This can lead to a lock splat
warning.

Fix this by freeing the path before we copy it to userspace.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/ioctl.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2759,6 +2759,8 @@ static int btrfs_ioctl_get_subvol_info(s
}
}

+ btrfs_free_path(path);
+ path = NULL;
if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
ret = -EFAULT;