From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Chris Mason Subject: [ 05/21] btrfs: Init io_lock after cloning btrfs device struct Date: Tue, 12 Mar 2013 15:44:07 -0700 Message-Id: <20130312223245.779061555@linuxfoundation.org> In-Reply-To: <20130312223245.109098379@linuxfoundation.org> References: <20130312223245.109098379@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 1cba0cdf5e4dbcd9e5fa5b54d7a028e55e2ca057 upstream. __btrfs_close_devices() clones btrfs device structs with memcpy(). Some of the fields in the clone are reinitialized, but it's missing to init io_lock. In mainline this goes unnoticed, but on RT it leaves the plist pointing to the original about to be freed lock struct. Initialize io_lock after cloning, so no references to the original struct are left. Reported-and-tested-by: Mike Galbraith Signed-off-by: Thomas Gleixner Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/volumes.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -512,6 +512,7 @@ static int __btrfs_close_devices(struct new_device->writeable = 0; new_device->in_fs_metadata = 0; new_device->can_discard = 0; + spin_lock_init(&new_device->io_lock); list_replace_rcu(&device->dev_list, &new_device->dev_list); call_rcu(&device->rcu, free_device);