From c60fcb1a18086c3050ff05c49f16ce4bf6d11421 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 [ Upstream commit e196c0e579902f42cf72414461fb034e5a1ffbf7 ] 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: Greg Kroah-Hartman --- drivers/net/bonding/bond_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index dc15d248443fd..21609f944b3be 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; }