tree ad530475217a5b3924aba3efa33125c345cf0a80
parent ac0a72a3e6e8d817f60ce4d9a8f3b43dc256d847
author Nikolay Aleksandrov <razor@blackwall.org> 1434389331 +0300
committer David S. Miller <davem@davemloft.net> 1434623387 -0700

bridge: fix br_stp_set_bridge_priority race conditions

After the ->set() spinlocks were removed br_stp_set_bridge_priority
was left running without any protection when used via sysfs. It can
race with port add/del and could result in use-after-free cases and
corrupted lists. Tested by running port add/del in a loop with stp
enabled while setting priority in a loop, crashes are easily
reproducible.
The spinlocks around sysfs ->set() were removed in commit:
14f98f258f19 ("bridge: range check STP parameters")
There's also a race condition in the netlink priority support that is
fixed by this change, but it was introduced recently and the fixes tag
covers it, just in case it's needed the commit is:
af615762e972 ("bridge: add ageing_time, stp_state, priority over netlink")

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Fixes: 14f98f258f19 ("bridge: range check STP parameters")
Signed-off-by: David S. Miller <davem@davemloft.net>