net: Fix bridgeing sysfs handling of rtnl_lock
Holding rtnl_lock when we are unregistering the sysfs files can
deadlock if we unconditionally take rtnl_lock in a sysfs file. So fix
it with the now familiar patter of: rtnl_trylock and syscall_restart()
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 02b2d50..4a3cdf8 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -189,7 +189,8 @@
val = simple_strtoul(buf, &endp, 0);
if (endp != buf) {
- rtnl_lock();
+ if (!rtnl_trylock())
+ return restart_syscall();
if (p->dev && p->br && brport_attr->store) {
spin_lock_bh(&p->br->lock);
ret = brport_attr->store(p, val);