From 2266bb1e122a4f7cdf3427defcfb48e5c6a8f205 Mon Sep 17 00:00:00 2001 From: Shay Drory Date: Mon, 13 Sep 2021 15:48:11 +0300 Subject: [PATCH] net/mlx5: Fix cleanup of bridge delayed work Currently, bridge cleanup is calling to cancel_delayed_work(). When this function is finished, there is a chance that the delayed work is still running. Also, the delayed work is queueing itself. As a result, we might execute the delayed work after the bridge cleanup have finished and hit a null-ptr oops[1]. Fix it by using cancel_delayed_work_sync(), which is waiting until the work is done and will cancel the queue work. [1] [ 8202.143043 ] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 8202.144438 ] #PF: supervisor write access in kernel mode [ 8202.145476 ] #PF: error_code(0x0002) - not-present page [ 8202.146520 ] PGD 0 P4D 0 [ 8202.147126 ] Oops: 0002 [#1] SMP NOPTI [ 8202.147899 ] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.14.0-rc6_for_upstream_min_debug_2021_08_25_16_06 #1 [ 8202.149741 ] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 8202.151908 ] RIP: 0010:_raw_spin_lock+0xc/0x20 [ 8202.156234 ] RSP: 0018:ffff88846f885ea0 EFLAGS: 00010046 [ 8202.157289 ] RAX: 0000000000000000 RBX: ffff88846f880000 RCX: 0000000000000000 [ 8202.158731 ] RDX: 0000000000000001 RSI: ffff8881004000c8 RDI: 0000000000000000 [ 8202.160177 ] RBP: ffff8881fe684978 R08: ffff888100140000 R09: ffffffff824455b8 [ 8202.161569 ] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [ 8202.163004 ] R13: 0000000000000012 R14: 0000000000000200 R15: ffff88812992d000 [ 8202.164018 ] FS: 0000000000000000(0000) GS:ffff88846f880000(0000) knlGS:0000000000000000 [ 8202.164960 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8202.165634 ] CR2: 0000000000000000 CR3: 0000000108cac004 CR4: 0000000000370ea0 [ 8202.166450 ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8202.167807 ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8202.168852 ] Call Trace: [ 8202.169421 ] [ 8202.169792 ] __queue_work+0xf2/0x3d0 [ 8202.170481 ] ? queue_work_node+0x40/0x40 [ 8202.171270 ] call_timer_fn+0x2b/0x100 [ 8202.171932 ] __run_timers.part.0+0x152/0x220 [ 8202.172717 ] ? __hrtimer_run_queues+0x171/0x290 [ 8202.173526 ] ? kvm_clock_get_cycles+0xd/0x10 [ 8202.174232 ] ? ktime_get+0x35/0x90 [ 8202.174943 ] run_timer_softirq+0x26/0x50 [ 8202.175745 ] __do_softirq+0xc7/0x271 [ 8202.176373 ] irq_exit_rcu+0x93/0xb0 [ 8202.176983 ] sysvec_apic_timer_interrupt+0x72/0x90 [ 8202.177755 ] [ 8202.178245 ] asm_sysvec_apic_timer_interrupt+0x12/0x20 Fixes: c636a0f0f3f0 ("net/mlx5: Bridge, dynamic entry ageing") Signed-off-by: Shay Drory Reviewed-by: Vlad Buslov Reviewed-by: Leon Romanovsky Reviewed-by: Maor Gottlieb Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c index b5ddaa8..c6d2f8c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bridge.c @@ -475,9 +475,6 @@ void mlx5e_rep_bridge_init(struct mlx5e_priv *priv) esw_warn(mdev, "Failed to allocate bridge offloads workqueue\n"); goto err_alloc_wq; } - INIT_DELAYED_WORK(&br_offloads->update_work, mlx5_esw_bridge_update_work); - queue_delayed_work(br_offloads->wq, &br_offloads->update_work, - msecs_to_jiffies(MLX5_ESW_BRIDGE_UPDATE_INTERVAL)); br_offloads->nb.notifier_call = mlx5_esw_bridge_switchdev_event; err = register_switchdev_notifier(&br_offloads->nb); @@ -500,6 +497,9 @@ void mlx5e_rep_bridge_init(struct mlx5e_priv *priv) err); goto err_register_netdev; } + INIT_DELAYED_WORK(&br_offloads->update_work, mlx5_esw_bridge_update_work); + queue_delayed_work(br_offloads->wq, &br_offloads->update_work, + msecs_to_jiffies(MLX5_ESW_BRIDGE_UPDATE_INTERVAL)); return; err_register_netdev: @@ -523,10 +523,10 @@ void mlx5e_rep_bridge_cleanup(struct mlx5e_priv *priv) if (!br_offloads) return; + cancel_delayed_work_sync(&br_offloads->update_work); unregister_netdevice_notifier(&br_offloads->netdev_nb); unregister_switchdev_blocking_notifier(&br_offloads->nb_blk); unregister_switchdev_notifier(&br_offloads->nb); - cancel_delayed_work(&br_offloads->update_work); destroy_workqueue(br_offloads->wq); rtnl_lock(); mlx5_esw_bridge_cleanup(esw); -- 2.7.4