From: Ido Schimmel <idosch@mellanox.com>
Date: Mon, 20 Jun 2016 08:53:20 +0000 (+0300)
Subject: team: Fix possible deadlock during team enslave
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=942f64c4c2be19a1b4a0c4295182b42d153899bf;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

team: Fix possible deadlock during team enslave

Both dev_uc_sync_multiple() and dev_mc_sync_multiple() require the
source device to be locked by netif_addr_lock_bh(), but this is missing
in team's enslave function, so add it.

This fixes the following lockdep warning:

Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(_xmit_ETHER/1);
                                local_irq_disable();
                                lock(&(&mc->mca_lock)->rlock);
                                lock(&team_netdev_addr_lock_key);
   <Interrupt>
     lock(&(&mc->mca_lock)->rlock);

  *** DEADLOCK ***

Fixes: cb41c997d444 ("team: team should sync the port's uc/mc addrs when add a port")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 2ace126533cd..fdee77207323 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1203,8 +1203,10 @@ static int team_port_add(struct team *team, struct net_device *port_dev)
 		goto err_dev_open;
 	}
 
+	netif_addr_lock_bh(dev);
 	dev_uc_sync_multiple(port_dev, dev);
 	dev_mc_sync_multiple(port_dev, dev);
+	netif_addr_unlock_bh(dev);
 
 	err = vlan_vids_add_by_dev(port_dev, dev);
 	if (err) {