From d62962b37cebdc936e2bfcd69ea685da2c433727 Mon Sep 17 00:00:00 2001 From: Mahesh Bandewar Date: Tue, 2 Jul 2019 23:16:31 -0700 Subject: loopback: fix lockdep splat dev_init_scheduler() and dev_activate() expect the caller to hold RTNL. Since we don't want blackhole device to be initialized per ns, we are initializing at init. [ 3.855027] Call Trace: [ 3.855034] dump_stack+0x67/0x95 [ 3.855037] lockdep_rcu_suspicious+0xd5/0x110 [ 3.855044] dev_init_scheduler+0xe3/0x120 [ 3.855048] ? net_olddevs_init+0x60/0x60 [ 3.855050] blackhole_netdev_init+0x45/0x6e [ 3.855052] do_one_initcall+0x6c/0x2fa [ 3.855058] ? rcu_read_lock_sched_held+0x8c/0xa0 [ 3.855066] kernel_init_freeable+0x1e5/0x288 [ 3.855071] ? rest_init+0x260/0x260 [ 3.855074] kernel_init+0xf/0x180 [ 3.855076] ? rest_init+0x260/0x260 [ 3.855078] ret_from_fork+0x24/0x30 Fixes: 4de83b88c66 ("loopback: create blackhole net device similar to loopack.") Reported-by: Geert Uytterhoeven Cc: Eric Dumazet Signed-off-by: Mahesh Bandewar Tested-by: Geert Uytterhoeven Signed-off-by: David S. Miller --- drivers/net/loopback.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/net/loopback.c') diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 3b39def5471e..14545a8797a8 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -261,8 +261,10 @@ static int __init blackhole_netdev_init(void) if (!blackhole_netdev) return -ENOMEM; + rtnl_lock(); dev_init_scheduler(blackhole_netdev); dev_activate(blackhole_netdev); + rtnl_unlock(); blackhole_netdev->flags |= IFF_UP | IFF_RUNNING; dev_net_set(blackhole_netdev, &init_net); -- cgit v1.2.3-59-g8ed1b