From: Anand Jain <anand.jain@oracle.com>
Date: Thu, 10 Nov 2022 06:06:31 +0000 (+0530)
Subject: btrfs: free btrfs_path before copying subvol info to userspace
X-Git-Tag: v6.1-rc7~17^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=013c1c5585ebcfb19c88efe79063d0463b1b6159;p=thirdparty%2Flinux.git

btrfs: free btrfs_path before copying subvol info to userspace

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>
---

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index df5b893494fad..5ba2e810dc6e0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3105,6 +3105,8 @@ static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
 		}
 	}
 
+	btrfs_free_path(path);
+	path = NULL;
 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
 		ret = -EFAULT;