6.6-stable review patch. If anyone has any objections, please let me know.
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From: Cosmin Ratiu cratiu@nvidia.com
commit 4dbc1d1a9f39c3711ad2a40addca04d07d9ab5d0 upstream.
When profile rollback fails in mlx5e_netdev_change_profile, the netdev profile var is left set to NULL. Avoid a crash when unloading the driver by not calling profile->cleanup in such a case.
This was encountered while testing, with the original trigger that the wq rescuer thread creation got interrupted (presumably due to Ctrl+C-ing modprobe), which gets converted to ENOMEM (-12) by mlx5e_priv_init, the profile rollback also fails for the same reason (signal still active) so the profile is left as NULL, leading to a crash later in _mlx5e_remove.
[ 732.473932] mlx5_core 0000:08:00.1: E-Switch: Unload vfs: mode(OFFLOADS), nvfs(2), necvfs(0), active vports(2) [ 734.525513] workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR [ 734.557372] mlx5_core 0000:08:00.1: mlx5e_netdev_init_profile:6235:(pid 6086): mlx5e_priv_init failed, err=-12 [ 734.559187] mlx5_core 0000:08:00.1 eth3: mlx5e_netdev_change_profile: new profile init failed, -12 [ 734.560153] workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR [ 734.589378] mlx5_core 0000:08:00.1: mlx5e_netdev_init_profile:6235:(pid 6086): mlx5e_priv_init failed, err=-12 [ 734.591136] mlx5_core 0000:08:00.1 eth3: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12 [ 745.537492] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 745.538222] #PF: supervisor read access in kernel mode <snipped> [ 745.551290] Call Trace: [ 745.551590] <TASK> [ 745.551866] ? __die+0x20/0x60 [ 745.552218] ? page_fault_oops+0x150/0x400 [ 745.555307] ? exc_page_fault+0x79/0x240 [ 745.555729] ? asm_exc_page_fault+0x22/0x30 [ 745.556166] ? mlx5e_remove+0x6b/0xb0 [mlx5_core] [ 745.556698] auxiliary_bus_remove+0x18/0x30 [ 745.557134] device_release_driver_internal+0x1df/0x240 [ 745.557654] bus_remove_device+0xd7/0x140 [ 745.558075] device_del+0x15b/0x3c0 [ 745.558456] mlx5_rescan_drivers_locked.part.0+0xb1/0x2f0 [mlx5_core] [ 745.559112] mlx5_unregister_device+0x34/0x50 [mlx5_core] [ 745.559686] mlx5_uninit_one+0x46/0xf0 [mlx5_core] [ 745.560203] remove_one+0x4e/0xd0 [mlx5_core] [ 745.560694] pci_device_remove+0x39/0xa0 [ 745.561112] device_release_driver_internal+0x1df/0x240 [ 745.561631] driver_detach+0x47/0x90 [ 745.562022] bus_remove_driver+0x84/0x100 [ 745.562444] pci_unregister_driver+0x3b/0x90 [ 745.562890] mlx5_cleanup+0xc/0x1b [mlx5_core] [ 745.563415] __x64_sys_delete_module+0x14d/0x2f0 [ 745.563886] ? kmem_cache_free+0x1b0/0x460 [ 745.564313] ? lockdep_hardirqs_on_prepare+0xe2/0x190 [ 745.564825] do_syscall_64+0x6d/0x140 [ 745.565223] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 745.565725] RIP: 0033:0x7f1579b1288b
Fixes: 3ef14e463f6e ("net/mlx5e: Separate between netdev objects and mlx5e profiles initialization") Signed-off-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Dragos Tatulea dtatulea@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Jianqi Ren jianqi.ren.cn@windriver.com Signed-off-by: He Zhe zhe.he@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -6110,7 +6110,9 @@ static void mlx5e_remove(struct auxiliar mlx5e_dcbnl_delete_app(priv); unregister_netdev(priv->netdev); mlx5e_suspend(adev, state); - priv->profile->cleanup(priv); + /* Avoid cleanup if profile rollback failed. */ + if (priv->profile) + priv->profile->cleanup(priv); mlx5e_destroy_netdev(priv); mlx5e_devlink_port_unregister(mlx5e_dev); mlx5e_destroy_devlink(mlx5e_dev);