From 496a60cdcd5d0d884dddf6c3b4ea912923a70f13 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 13 May 2009 17:02:50 +0000 Subject: [PATCH] net: FIX bonding sysfs rtnl_lock deadlock Sysfs files for a network device can not unconditionally take the rtnl_lock as the bonding sysfs files do. If someone accesses those sysfs files while the network device is being unregistered with the rtnl_lock held we will deadlock. So use trylock and restart_syscall to avoid this problem. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- drivers/net/bonding/bond_sysfs.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index d28731535226..3a1b7b04eb79 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -251,7 +251,8 @@ static ssize_t bonding_store_slaves(struct device *d, /* Note: We can't hold bond->lock here, as bond_create grabs it. */ - rtnl_lock(); + if (!rtnl_trylock()) + return restart_syscall(); down_write(&(bonding_rwsem)); sscanf(buffer, "%16s", command); /* IFNAMSIZ*/ @@ -1171,7 +1172,8 @@ static ssize_t bonding_store_primary(struct device *d, struct slave *slave; struct bonding *bond = to_bond(d); - rtnl_lock(); + if (!rtnl_trylock()) + return restart_syscall(); read_lock(&bond->lock); write_lock_bh(&bond->curr_slave_lock); @@ -1288,7 +1290,8 @@ static ssize_t bonding_store_active_slave(struct device *d, struct slave *new_active = NULL; struct bonding *bond = to_bond(d); - rtnl_lock(); + if (!rtnl_trylock()) + return restart_syscall(); read_lock(&bond->lock); write_lock_bh(&bond->curr_slave_lock);