From patchwork Wed Jan 9 16:55:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.y.z, extended, stable] Patch "bonding: fix race condition in bonding_store_slaves_active" has been added to staging queue Date: Wed, 09 Jan 2013 06:55:38 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 210770 Message-Id: <1357750538-25151-1-git-send-email-herton.krzesinski@canonical.com> To: "nikolay@redhat.com" Cc: kernel-team@lists.ubuntu.com, Jay Vosburgh , "David S. Miller" This is a note to let you know that I have just added a patch titled bonding: fix race condition in bonding_store_slaves_active to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ >From 8bbcd221182e27fd816f23f22427c7ddcc4432af Mon Sep 17 00:00:00 2001 From: "nikolay@redhat.com" Date: Thu, 29 Nov 2012 01:37:59 +0000 Subject: [PATCH] bonding: fix race condition in bonding_store_slaves_active commit e196c0e579902f42cf72414461fb034e5a1ffbf7 upstream. Race between bonding_store_slaves_active() and slave manipulation functions. The bond_for_each_slave use in bonding_store_slaves_active() is not protected by any synchronization mechanism. NULL pointer dereference is easy to reach. Fixed by acquiring the bond->lock for the slave walk. v2: Make description text < 75 columns Signed-off-by: Nikolay Aleksandrov Signed-off-by: Jay Vosburgh Signed-off-by: David S. Miller Signed-off-by: Herton Ronaldo Krzesinski --- drivers/net/bonding/bond_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.7.9.5 diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index 485bedb..9ea29aa 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -1582,6 +1582,7 @@ static ssize_t bonding_store_slaves_active(struct device *d, goto out; } + read_lock(&bond->lock); bond_for_each_slave(bond, slave, i) { if (!bond_is_active_slave(slave)) { if (new_value) @@ -1590,6 +1591,7 @@ static ssize_t bonding_store_slaves_active(struct device *d, slave->inactive = 1; } } + read_unlock(&bond->lock); out: return ret; }