From: Eric Dumazet edumazet@google.com
[ Upstream commit 42c7ded0eeacd2ba5db599205c71c279dc715de7 ]
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: e95cc44763a4 ("bonding: do failover when high prio link up") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot 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: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/bonding/bond_main.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index b108f2f4adc2..fce9301c8ebb 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2653,10 +2653,12 @@ 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: @@ -2699,8 +2701,8 @@ 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;