[PATCH 4.20 67/80] btrfs: On error always free subvol_name in btrfs_mount

Greg Kroah-Hartman
2019-02-04T10:55:59Z

From: Eric W. Biederman <ebiederm@xmission.com>

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@vger.kernel.org # v4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.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/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;
}