This is a note to let you know that I've just added the patch titled btrfs: free btrfs_path before copying subvol info to userspace to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-free-btrfs_path-before-copying-subvol-info-to-userspace.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 013c1c5585ebcfb19c88efe79063d0463b1b6159 Mon Sep 17 00:00:00 2001 From: Anand Jain <anand.jain@xxxxxxxxxx> Date: Thu, 10 Nov 2022 11:36:31 +0530 Subject: btrfs: free btrfs_path before copying subvol info to userspace From: Anand Jain <anand.jain@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx # 4.19+ Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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; Patches currently in stable-queue which might be from anand.jain@xxxxxxxxxx are queue-4.19/btrfs-free-btrfs_path-before-copying-fspath-to-userspace.patch queue-4.19/btrfs-free-btrfs_path-before-copying-subvol-info-to-userspace.patch queue-4.19/btrfs-free-btrfs_path-before-copying-root-refs-to-userspace.patch