Commit 42c7ded0 authored by Eric Dumazet's avatar Eric Dumazet Committed by Paolo Abeni
Browse files

bonding: fix lockdep splat in bond_miimon_commit() 



bond_miimon_commit() is run while RTNL is held, not RCU.

WARNING: suspicious RCU usage
6.1.0-syzkaller-09671-g89529367293c #0 Not tainted
-----------------------------
drivers/net/bonding/bond_main.c:2704 suspicious rcu_dereference_check() usage!

Fixes: e95cc447 ("bonding: do failover when high prio link up")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Cc: Hangbin Liu <liuhangbin@gmail.com>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Link: https://lore.kernel.org/r/20221220130831.1480888-1-edumazet@google.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 43ae218f

drivers/net/bonding/bond_main.c

+5 −3
Original line number Diff line number Diff line
@@ -2654,10 +2654,12 @@ static void bond_miimon_link_change(struct bonding *bond, 


static void bond_miimon_commit(struct bonding *bond)

{

	struct slave *slave, *primary;

	struct slave *slave, *primary, *active;

	bool do_failover = false;

	struct list_head *iter;



	ASSERT_RTNL();



	bond_for_each_slave(bond, slave, iter) {

		switch (slave->link_new_state) {

		case BOND_LINK_NOCHANGE:
@@ -2700,8 +2702,8 @@ static void bond_miimon_commit(struct bonding *bond) 


			bond_miimon_link_change(bond, slave, BOND_LINK_UP);



			if (!rcu_access_pointer(bond->curr_active_slave) || slave == primary ||

			    slave->prio > rcu_dereference(bond->curr_active_slave)->prio)

			active = rtnl_dereference(bond->curr_active_slave);

			if (!active || slave == primary || slave->prio > active->prio)

				do_failover = true;



			continue;