From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934496Ab2AJXD7 (ORCPT ); Tue, 10 Jan 2012 18:03:59 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52837 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934482Ab2AJXDw (ORCPT ); Tue, 10 Jan 2012 18:03:52 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Jan 10 13:56:05 2012 Message-Id: <20120110215605.644114899@clark.kroah.org> User-Agent: quilt/0.50-25.1 Date: Tue, 10 Jan 2012 13:55:50 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Stephen Hemminger , "David S. Miller" Subject: [47/49] bonding: fix error handling if slave is busy (v2) In-Reply-To: <20120110215609.GA22505@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: stephen hemminger commit f7d9821a6a9c83450ac35e76d3709e32fd38b76f upstream. If slave device already has a receive handler registered, then the error unwind of bonding device enslave function is broken. The following will leave a pointer to freed memory in the slave device list, causing a later kernel panic. # modprobe dummy # ip li add dummy0-1 link dummy0 type macvlan # modprobe bonding # echo +dummy0 >/sys/class/net/bond0/bonding/slaves The fix is to detach the slave (which removes it from the list) in the unwind path. Signed-off-by: Stephen Hemminger Reviewed-by: Nicolas de Pesloüan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/bonding/bond_main.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1822,7 +1822,7 @@ int bond_enslave(struct net_device *bond "but new slave device does not support netpoll.\n", bond_dev->name); res = -EBUSY; - goto err_close; + goto err_detach; } } #endif @@ -1831,7 +1831,7 @@ int bond_enslave(struct net_device *bond res = bond_create_slave_symlinks(bond_dev, slave_dev); if (res) - goto err_close; + goto err_detach; res = netdev_rx_handler_register(slave_dev, bond_handle_frame, new_slave); @@ -1852,6 +1852,11 @@ int bond_enslave(struct net_device *bond err_dest_symlinks: bond_destroy_slave_symlinks(bond_dev, slave_dev); +err_detach: + write_lock_bh(&bond->lock); + bond_detach_slave(bond, new_slave); + write_unlock_bh(&bond->lock); + err_close: dev_close(slave_dev);