[PATCH 4.19 60/74] btrfs: On error always free subvol_name in btrfs_mount

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>

commit 532b618bdf237250d6d4566536d4b6ce3d0a31fe upstream.

The subvol_name is allocated in btrfs_parse_subvol_options and is
consumed and freed in mount_subvol.  Add a free to the error paths that
don't call mount_subvol so that it is guaranteed that subvol_name is
freed when an error happens.

Fixes: 312c89fbca06 ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()")
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/btrfs/super.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1677,6 +1677,7 @@ static struct dentry *btrfs_mount(struct
 				flags | SB_RDONLY, device_name, data);
 			if (IS_ERR(mnt_root)) {
 				root = ERR_CAST(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 
@@ -1686,12 +1687,14 @@ static struct dentry *btrfs_mount(struct
 			if (error < 0) {
 				root = ERR_PTR(error);
 				mntput(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 		}
 	}
 	if (IS_ERR(mnt_root)) {
 		root = ERR_CAST(mnt_root);
+		kfree(subvol_name);
 		goto out;
 	}