net/mlx5: Initialize flow steering during driver probe

Currently, software objects of flow steering are created and destroyed
during reload flow. In case a device is unloaded, the following error
is printed during grace period:

 mlx5_core 0000:00:0b.0: mlx5_fw_fatal_reporter_err_work:690:(pid 95):
    Driver is in error state. Unloading

As a solution to fix use-after-free bugs, where we try to access
these objects, when reading the value of flow_steering_mode devlink
param[1], let's split flow steering creation and destruction into two
routines:
    * init and cleanup: memory, cache, and pools allocation/free.
    * create and destroy: namespaces initialization and cleanup.

While at it, re-order the cleanup function to mirror the init function.

[1]
Kasan trace:

[  385.119849 ] BUG: KASAN: use-after-free in mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ] Read of size 4 at addr ffff888104b79308 by task bash/291
[  385.119849 ]
[  385.119849 ] CPU: 1 PID: 291 Comm: bash Not tainted 5.17.0-rc1+ #2
[  385.119849 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
[  385.119849 ] Call Trace:
[  385.119849 ]  <TASK>
[  385.119849 ]  dump_stack_lvl+0x6e/0x91
[  385.119849 ]  print_address_description.constprop.0+0x1f/0x160
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  kasan_report.cold+0x83/0xdf
[  385.119849 ]  ? devlink_param_notify+0x20/0x190
[  385.119849 ]  ? mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  mlx5_devlink_fs_mode_get+0x3b/0xa0
[  385.119849 ]  devlink_nl_param_fill+0x18a/0xa50
[  385.119849 ]  ? _raw_spin_lock_irqsave+0x8d/0xe0
[  385.119849 ]  ? devlink_flash_update_timeout_notify+0xf0/0xf0
[  385.119849 ]  ? __wake_up_common+0x4b/0x1e0
[  385.119849 ]  ? preempt_count_sub+0x14/0xc0
[  385.119849 ]  ? _raw_spin_unlock_irqrestore+0x28/0x40
[  385.119849 ]  ? __wake_up_common_lock+0xe3/0x140
[  385.119849 ]  ? __wake_up_common+0x1e0/0x1e0
[  385.119849 ]  ? __sanitizer_cov_trace_const_cmp8+0x27/0x80
[  385.119849 ]  ? __rcu_read_unlock+0x48/0x70
[  385.119849 ]  ? kasan_unpoison+0x23/0x50
[  385.119849 ]  ? __kasan_slab_alloc+0x2c/0x80
[  385.119849 ]  ? memset+0x20/0x40
[  385.119849 ]  ? __sanitizer_cov_trace_const_cmp4+0x25/0x80
[  385.119849 ]  devlink_param_notify+0xce/0x190
[  385.119849 ]  devlink_unregister+0x92/0x2b0
[  385.119849 ]  remove_one+0x41/0x140
[  385.119849 ]  pci_device_remove+0x68/0x140
[  385.119849 ]  ? pcibios_free_irq+0x10/0x10
[  385.119849 ]  __device_release_driver+0x294/0x3f0
[  385.119849 ]  device_driver_detach+0x82/0x130
[  385.119849 ]  unbind_store+0x193/0x1b0
[  385.119849 ]  ? subsys_interface_unregister+0x270/0x270
[  385.119849 ]  drv_attr_store+0x4e/0x70
[  385.119849 ]  ? drv_attr_show+0x60/0x60
[  385.119849 ]  sysfs_kf_write+0xa7/0xc0
[  385.119849 ]  kernfs_fop_write_iter+0x23a/0x2f0
[  385.119849 ]  ? sysfs_kf_bin_read+0x160/0x160
[  385.119849 ]  new_sync_write+0x311/0x430
[  385.119849 ]  ? new_sync_read+0x480/0x480
[  385.119849 ]  ? _raw_spin_lock+0x87/0xe0
[  385.119849 ]  ? __sanitizer_cov_trace_cmp4+0x25/0x80
[  385.119849 ]  ? security_file_permission+0x94/0xa0
[  385.119849 ]  vfs_write+0x4c7/0x590
[  385.119849 ]  ksys_write+0xf6/0x1e0
[  385.119849 ]  ? __x64_sys_read+0x50/0x50
[  385.119849 ]  ? fpregs_assert_state_consistent+0x99/0xa0
[  385.119849 ]  do_syscall_64+0x3d/0x90
[  385.119849 ]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  385.119849 ] RIP: 0033:0x7fc36ef38504
[  385.119849 ] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f
80 00 00 00 00 48 8d 05 f9 61 0d 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f
05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 49 89 d4 55 48 89 f5 53
[  385.119849 ] RSP: 002b:00007ffde0ff3d08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  385.119849 ] RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc36ef38504
[  385.119849 ] RDX: 000000000000000c RSI: 00007fc370521040 RDI: 0000000000000001
[  385.119849 ] RBP: 00007fc370521040 R08: 00007fc36f00b8c0 R09: 00007fc36ee4b740
[  385.119849 ] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc36f00a760
[  385.119849 ] R13: 000000000000000c R14: 00007fc36f005760 R15: 000000000000000c
[  385.119849 ]  </TASK>
[  385.119849 ]
[  385.119849 ] Allocated by task 65:
[  385.119849 ]  kasan_save_stack+0x1e/0x40
[  385.119849 ]  __kasan_kmalloc+0x81/0xa0
[  385.119849 ]  mlx5_init_fs+0x11b/0x1160
[  385.119849 ]  mlx5_load+0x13c/0x220
[  385.119849 ]  mlx5_load_one+0xda/0x160
[  385.119849 ]  mlx5_recover_device+0xb8/0x100
[  385.119849 ]  mlx5_health_try_recover+0x2f9/0x3a1
[  385.119849 ]  devlink_health_reporter_recover+0x75/0x100
[  385.119849 ]  devlink_health_report+0x26c/0x4b0
[  385.275909 ]  mlx5_fw_fatal_reporter_err_work+0x11e/0x1b0
[  385.275909 ]  process_one_work+0x520/0x970
[  385.275909 ]  worker_thread+0x378/0x950
[  385.275909 ]  kthread+0x1bb/0x200
[  385.275909 ]  ret_from_fork+0x1f/0x30
[  385.275909 ]
[  385.275909 ] Freed by task 65:
[  385.275909 ]  kasan_save_stack+0x1e/0x40
[  385.275909 ]  kasan_set_track+0x21/0x30
[  385.275909 ]  kasan_set_free_info+0x20/0x30
[  385.275909 ]  __kasan_slab_free+0xfc/0x140
[  385.275909 ]  kfree+0xa5/0x3b0
[  385.275909 ]  mlx5_unload+0x2e/0xb0
[  385.275909 ]  mlx5_unload_one+0x86/0xb0
[  385.275909 ]  mlx5_fw_fatal_reporter_err_work.cold+0xca/0xcf
[  385.275909 ]  process_one_work+0x520/0x970
[  385.275909 ]  worker_thread+0x378/0x950
[  385.275909 ]  kthread+0x1bb/0x200
[  385.275909 ]  ret_from_fork+0x1f/0x30
[  385.275909 ]
[  385.275909 ] The buggy address belongs to the object at ffff888104b79300
[  385.275909 ]  which belongs to the cache kmalloc-128 of size 128
[  385.275909 ] The buggy address is located 8 bytes inside of
[  385.275909 ]  128-byte region [ffff888104b79300, ffff888104b79380)
[  385.275909 ] The buggy address belongs to the page:
[  385.275909 ] page:00000000de44dd39 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104b78
[  385.275909 ] head:00000000de44dd39 order:1 compound_mapcount:0
[  385.275909 ] flags: 0x8000000000010200(slab|head|zone=2)
[  385.275909 ] raw: 8000000000010200 0000000000000000 dead000000000122 ffff8881000428c0
[  385.275909 ] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[  385.275909 ] page dumped because: kasan: bad access detected
[  385.275909 ]
[  385.275909 ] Memory state around the buggy address:
[  385.275909 ]  ffff888104b79200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
[  385.275909 ]  ffff888104b79280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  385.275909 ] >ffff888104b79300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  385.275909 ]                       ^
[  385.275909 ]  ffff888104b79380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  385.275909 ]  ffff888104b79400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  385.275909 ]]

Fixes: e890acd5 ("net/mlx5: Add devlink flow_steering_mode parameter")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

@@ -2663,28 +2663,6 @@ static void cleanup_root_ns(struct mlx5_flow_root_namespace *root_ns)
 	clean_tree(&root_ns->ns.node);
 }
 
-void mlx5_cleanup_fs(struct mlx5_core_dev *dev)
-{
-	struct mlx5_flow_steering *steering = dev->priv.steering;
-
-	cleanup_root_ns(steering->root_ns);
-	cleanup_root_ns(steering->fdb_root_ns);
-	steering->fdb_root_ns = NULL;
-	kfree(steering->fdb_sub_ns);
-	steering->fdb_sub_ns = NULL;
-	cleanup_root_ns(steering->port_sel_root_ns);
-	cleanup_root_ns(steering->sniffer_rx_root_ns);
-	cleanup_root_ns(steering->sniffer_tx_root_ns);
-	cleanup_root_ns(steering->rdma_rx_root_ns);
-	cleanup_root_ns(steering->rdma_tx_root_ns);
-	cleanup_root_ns(steering->egress_root_ns);
-	mlx5_cleanup_fc_stats(dev);
-	kmem_cache_destroy(steering->ftes_cache);
-	kmem_cache_destroy(steering->fgs_cache);
-	mlx5_ft_pool_destroy(dev);
-	kfree(steering);
-}
-
 static int init_sniffer_tx_root_ns(struct mlx5_flow_steering *steering)
 {
 	struct fs_prio *prio;
@@ -3086,42 +3064,27 @@ static int init_egress_root_ns(struct mlx5_flow_steering *steering)
 	return err;
 }
 
-int mlx5_init_fs(struct mlx5_core_dev *dev)
+void mlx5_fs_core_cleanup(struct mlx5_core_dev *dev)
 {
-	struct mlx5_flow_steering *steering;
-	int err = 0;
-
-	err = mlx5_init_fc_stats(dev);
-	if (err)
-		return err;
-
-	err = mlx5_ft_pool_init(dev);
-	if (err)
-		return err;
-
-	steering = kzalloc(sizeof(*steering), GFP_KERNEL);
-	if (!steering) {
-		err = -ENOMEM;
-		goto err;
-	}
-
-	steering->dev = dev;
-	dev->priv.steering = steering;
+	struct mlx5_flow_steering *steering = dev->priv.steering;
 
-	if (mlx5_fs_dr_is_supported(dev))
-		steering->mode = MLX5_FLOW_STEERING_MODE_SMFS;
-	else
-		steering->mode = MLX5_FLOW_STEERING_MODE_DMFS;
+	cleanup_root_ns(steering->root_ns);
+	cleanup_root_ns(steering->fdb_root_ns);
+	steering->fdb_root_ns = NULL;
+	kfree(steering->fdb_sub_ns);
+	steering->fdb_sub_ns = NULL;
+	cleanup_root_ns(steering->port_sel_root_ns);
+	cleanup_root_ns(steering->sniffer_rx_root_ns);
+	cleanup_root_ns(steering->sniffer_tx_root_ns);
+	cleanup_root_ns(steering->rdma_rx_root_ns);
+	cleanup_root_ns(steering->rdma_tx_root_ns);
+	cleanup_root_ns(steering->egress_root_ns);
+}
 
-	steering->fgs_cache = kmem_cache_create("mlx5_fs_fgs",
-						sizeof(struct mlx5_flow_group), 0,
-						0, NULL);
-	steering->ftes_cache = kmem_cache_create("mlx5_fs_ftes", sizeof(struct fs_fte), 0,
-						 0, NULL);
-	if (!steering->ftes_cache || !steering->fgs_cache) {
-		err = -ENOMEM;
-		goto err;
-	}
+int mlx5_fs_core_init(struct mlx5_core_dev *dev)
+{
+	struct mlx5_flow_steering *steering = dev->priv.steering;
+	int err = 0;
 
 	if ((((MLX5_CAP_GEN(dev, port_type) == MLX5_CAP_PORT_TYPE_ETH) &&
 	      (MLX5_CAP_GEN(dev, nic_flow_table))) ||
@@ -3180,8 +3143,64 @@ int mlx5_init_fs(struct mlx5_core_dev *dev)
 	}
 
 	return 0;
+
+err:
+	mlx5_fs_core_cleanup(dev);
+	return err;
+}
+
+void mlx5_fs_core_free(struct mlx5_core_dev *dev)
+{
+	struct mlx5_flow_steering *steering = dev->priv.steering;
+
+	kmem_cache_destroy(steering->ftes_cache);
+	kmem_cache_destroy(steering->fgs_cache);
+	kfree(steering);
+	mlx5_ft_pool_destroy(dev);
+	mlx5_cleanup_fc_stats(dev);
+}
+
+int mlx5_fs_core_alloc(struct mlx5_core_dev *dev)
+{
+	struct mlx5_flow_steering *steering;
+	int err = 0;
+
+	err = mlx5_init_fc_stats(dev);
+	if (err)
+		return err;
+
+	err = mlx5_ft_pool_init(dev);
+	if (err)
+		goto err;
+
+	steering = kzalloc(sizeof(*steering), GFP_KERNEL);
+	if (!steering) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	steering->dev = dev;
+	dev->priv.steering = steering;
+
+	if (mlx5_fs_dr_is_supported(dev))
+		steering->mode = MLX5_FLOW_STEERING_MODE_SMFS;
+	else
+		steering->mode = MLX5_FLOW_STEERING_MODE_DMFS;
+
+	steering->fgs_cache = kmem_cache_create("mlx5_fs_fgs",
+						sizeof(struct mlx5_flow_group), 0,
+						0, NULL);
+	steering->ftes_cache = kmem_cache_create("mlx5_fs_ftes", sizeof(struct fs_fte), 0,
+						 0, NULL);
+	if (!steering->ftes_cache || !steering->fgs_cache) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	return 0;
+
 err:
-	mlx5_cleanup_fs(dev);
+	mlx5_fs_core_free(dev);
 	return err;
 }
 

drivers/net/ethernet/mellanox/mlx5/core/fs_core.h

@@ -298,8 +298,10 @@ int mlx5_flow_namespace_set_peer(struct mlx5_flow_root_namespace *ns,
 int mlx5_flow_namespace_set_mode(struct mlx5_flow_namespace *ns,
 				 enum mlx5_flow_steering_mode mode);
 
-int mlx5_init_fs(struct mlx5_core_dev *dev);
-void mlx5_cleanup_fs(struct mlx5_core_dev *dev);
+int mlx5_fs_core_alloc(struct mlx5_core_dev *dev);
+void mlx5_fs_core_free(struct mlx5_core_dev *dev);
+int mlx5_fs_core_init(struct mlx5_core_dev *dev);
+void mlx5_fs_core_cleanup(struct mlx5_core_dev *dev);
 
 int mlx5_fs_egress_acls_init(struct mlx5_core_dev *dev, int total_vports);
 void mlx5_fs_egress_acls_cleanup(struct mlx5_core_dev *dev);

drivers/net/ethernet/mellanox/mlx5/core/main.c

@@ -938,6 +938,12 @@ static int mlx5_init_once(struct mlx5_core_dev *dev)
 		goto err_sf_table_cleanup;
 	}
 
+	err = mlx5_fs_core_alloc(dev);
+	if (err) {
+		mlx5_core_err(dev, "Failed to alloc flow steering\n");
+		goto err_fs;
+	}
+
 	dev->dm = mlx5_dm_create(dev);
 	if (IS_ERR(dev->dm))
 		mlx5_core_warn(dev, "Failed to init device memory%d\n", err);
@@ -948,6 +954,8 @@ static int mlx5_init_once(struct mlx5_core_dev *dev)
 
 	return 0;
 
+err_fs:
+	mlx5_sf_table_cleanup(dev);
 err_sf_table_cleanup:
 	mlx5_sf_hw_table_cleanup(dev);
 err_sf_hw_table_cleanup:
@@ -985,6 +993,7 @@ static void mlx5_cleanup_once(struct mlx5_core_dev *dev)
 	mlx5_hv_vhca_destroy(dev->hv_vhca);
 	mlx5_fw_tracer_destroy(dev->tracer);
 	mlx5_dm_cleanup(dev);
+	mlx5_fs_core_free(dev);
 	mlx5_sf_table_cleanup(dev);
 	mlx5_sf_hw_table_cleanup(dev);
 	mlx5_vhca_event_cleanup(dev);
@@ -1191,7 +1200,7 @@ static int mlx5_load(struct mlx5_core_dev *dev)
 		goto err_tls_start;
 	}
 
-	err = mlx5_init_fs(dev);
+	err = mlx5_fs_core_init(dev);
 	if (err) {
 		mlx5_core_err(dev, "Failed to init flow steering\n");
 		goto err_fs;
@@ -1236,7 +1245,7 @@ static int mlx5_load(struct mlx5_core_dev *dev)
 err_vhca:
 	mlx5_vhca_event_stop(dev);
 err_set_hca:
-	mlx5_cleanup_fs(dev);
+	mlx5_fs_core_cleanup(dev);
 err_fs:
 	mlx5_accel_tls_cleanup(dev);
 err_tls_start:
@@ -1265,7 +1274,7 @@ static void mlx5_unload(struct mlx5_core_dev *dev)
 	mlx5_ec_cleanup(dev);
 	mlx5_sf_hw_table_destroy(dev);
 	mlx5_vhca_event_stop(dev);
-	mlx5_cleanup_fs(dev);
+	mlx5_fs_core_cleanup(dev);
 	mlx5_accel_ipsec_cleanup(dev);
 	mlx5_accel_tls_cleanup(dev);
 	mlx5_fpga_device_stop(dev);