From: Leon Romanovsky leonro@nvidia.com
[ Upstream commit 05a7f4a8dff19999ca8a83a35ff4782689de7bfc ]
The change of namespaces during devlink reload calls to driver unload before it accesses devlink parameters. The commands below causes to use-after-free bug when trying to get flow steering mode.
* ip netns add n1 * devlink dev reload pci/0000:00:09.0 netns n1
================================================================== BUG: KASAN: use-after-free in mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core] Read of size 4 at addr ffff888009d04308 by task devlink/275
CPU: 6 PID: 275 Comm: devlink Not tainted 5.12.0-rc2+ #2853 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x93/0xc2 print_address_description.constprop.0+0x18/0x140 ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core] ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core] kasan_report.cold+0x7c/0xd8 ? mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core] mlx5_devlink_fs_mode_get+0x96/0xa0 [mlx5_core] devlink_nl_param_fill+0x1c8/0xe80 ? __free_pages_ok+0x37a/0x8a0 ? devlink_flash_update_timeout_notify+0xd0/0xd0 ? lock_acquire+0x1a9/0x6d0 ? fs_reclaim_acquire+0xb7/0x160 ? lock_is_held_type+0x98/0x110 ? 0xffffffff81000000 ? lock_release+0x1f9/0x6c0 ? fs_reclaim_release+0xa1/0xf0 ? lock_downgrade+0x6d0/0x6d0 ? lock_is_held_type+0x98/0x110 ? lock_is_held_type+0x98/0x110 ? memset+0x20/0x40 ? __build_skb_around+0x1f8/0x2b0 devlink_param_notify+0x6d/0x180 devlink_reload+0x1c3/0x520 ? devlink_remote_reload_actions_performed+0x30/0x30 ? mutex_trylock+0x24b/0x2d0 ? devlink_nl_cmd_reload+0x62b/0x1070 devlink_nl_cmd_reload+0x66d/0x1070 ? devlink_reload+0x520/0x520 ? devlink_get_from_attrs+0x1bc/0x260 ? devlink_nl_pre_doit+0x64/0x4d0 genl_family_rcv_msg_doit+0x1e9/0x2f0 ? mutex_lock_io_nested+0x1130/0x1130 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240 ? security_capable+0x51/0x90 genl_rcv_msg+0x27f/0x4a0 ? genl_get_cmd+0x3c0/0x3c0 ? lock_acquire+0x1a9/0x6d0 ? devlink_reload+0x520/0x520 ? lock_release+0x6c0/0x6c0 netlink_rcv_skb+0x11d/0x340 ? genl_get_cmd+0x3c0/0x3c0 ? netlink_ack+0x9f0/0x9f0 ? lock_release+0x1f9/0x6c0 genl_rcv+0x24/0x40 netlink_unicast+0x433/0x700 ? netlink_attachskb+0x730/0x730 ? _copy_from_iter_full+0x178/0x650 ? __alloc_skb+0x113/0x2b0 netlink_sendmsg+0x6f1/0xbd0 ? netlink_unicast+0x700/0x700 ? lock_is_held_type+0x98/0x110 ? netlink_unicast+0x700/0x700 sock_sendmsg+0xb0/0xe0 __sys_sendto+0x193/0x240 ? __x64_sys_getpeername+0xb0/0xb0 ? do_sys_openat2+0x10b/0x370 ? __up_read+0x1a1/0x7b0 ? do_user_addr_fault+0x219/0xdc0 ? __x64_sys_openat+0x120/0x1d0 ? __x64_sys_open+0x1a0/0x1a0 __x64_sys_sendto+0xdd/0x1b0 ? syscall_enter_from_user_mode+0x1d/0x50 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc69d0af14a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 c3 0f 1f 44 00 00 55 48 83 ec 30 44 89 4c RSP: 002b:00007ffc1d8292f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fc69d0af14a RDX: 0000000000000038 RSI: 0000555f57c56440 RDI: 0000000000000003 RBP: 0000555f57c56410 R08: 00007fc69d17b200 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 146: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x99/0xc0 mlx5_init_fs+0xf0/0x1c50 [mlx5_core] mlx5_load+0xd2/0x180 [mlx5_core] mlx5_init_one+0x2f6/0x450 [mlx5_core] probe_one+0x47d/0x6e0 [mlx5_core] pci_device_probe+0x2a0/0x4a0 really_probe+0x20a/0xc90 driver_probe_device+0xd8/0x380 device_driver_attach+0x1df/0x250 __driver_attach+0xff/0x240 bus_for_each_dev+0x11e/0x1a0 bus_add_driver+0x309/0x570 driver_register+0x1ee/0x380 0xffffffffa06b8062 do_one_initcall+0xd5/0x410 do_init_module+0x1c8/0x760 load_module+0x6d8b/0x9650 __do_sys_finit_module+0x118/0x1b0 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 275: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x102/0x140 slab_free_freelist_hook+0x74/0x1b0 kfree+0xd7/0x2a0 mlx5_unload+0x16/0xb0 [mlx5_core] mlx5_unload_one+0xae/0x120 [mlx5_core] mlx5_devlink_reload_down+0x1bc/0x380 [mlx5_core] devlink_reload+0x141/0x520 devlink_nl_cmd_reload+0x66d/0x1070 genl_family_rcv_msg_doit+0x1e9/0x2f0 genl_rcv_msg+0x27f/0x4a0 netlink_rcv_skb+0x11d/0x340 genl_rcv+0x24/0x40 netlink_unicast+0x433/0x700 netlink_sendmsg+0x6f1/0xbd0 sock_sendmsg+0xb0/0xe0 __sys_sendto+0x193/0x240 __x64_sys_sendto+0xdd/0x1b0 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff888009d04300 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 8 bytes inside of 128-byte region [ffff888009d04300, ffff888009d04380) The buggy address belongs to the page: page:0000000086a64ecc refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888009d04000 pfn:0x9d04 head:0000000086a64ecc order:1 compound_mapcount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0000203980 0000000200000002 ffff8880050428c0 raw: ffff888009d04000 000000008020001d 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff888009d04200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888009d04280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888009d04300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff888009d04380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888009d04400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
The right solution to devlink reload is to notify about deletion of parameters, unload driver, change net namespaces, load driver and notify about addition of parameters.
Fixes: 070c63f20f6c ("net: devlink: allow to change namespaces during reload") Reviewed-by: Parav Pandit parav@nvidia.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/devlink.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/net/core/devlink.c b/net/core/devlink.c index 051432ea4f69..170e44f5e7df 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -3283,10 +3283,12 @@ static void devlink_param_notify(struct devlink *devlink, struct devlink_param_item *param_item, enum devlink_command cmd);
-static void devlink_reload_netns_change(struct devlink *devlink, - struct net *dest_net) +static void devlink_ns_change_notify(struct devlink *devlink, + struct net *dest_net, struct net *curr_net, + bool new) { struct devlink_param_item *param_item; + enum devlink_command cmd;
/* Userspace needs to be notified about devlink objects * removed from original and entering new network namespace. @@ -3294,17 +3296,18 @@ static void devlink_reload_netns_change(struct devlink *devlink, * reload process so the notifications are generated separatelly. */
- list_for_each_entry(param_item, &devlink->param_list, list) - devlink_param_notify(devlink, 0, param_item, - DEVLINK_CMD_PARAM_DEL); - devlink_notify(devlink, DEVLINK_CMD_DEL); + if (!dest_net || net_eq(dest_net, curr_net)) + return;
- __devlink_net_set(devlink, dest_net); + if (new) + devlink_notify(devlink, DEVLINK_CMD_NEW);
- devlink_notify(devlink, DEVLINK_CMD_NEW); + cmd = new ? DEVLINK_CMD_PARAM_NEW : DEVLINK_CMD_PARAM_DEL; list_for_each_entry(param_item, &devlink->param_list, list) - devlink_param_notify(devlink, 0, param_item, - DEVLINK_CMD_PARAM_NEW); + devlink_param_notify(devlink, 0, param_item, cmd); + + if (!new) + devlink_notify(devlink, DEVLINK_CMD_DEL); }
static bool devlink_reload_supported(const struct devlink_ops *ops) @@ -3384,6 +3387,7 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net, u32 *actions_performed, struct netlink_ext_ack *extack) { u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE]; + struct net *curr_net; int err;
if (!devlink->reload_enabled) @@ -3391,18 +3395,22 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net,
memcpy(remote_reload_stats, devlink->stats.remote_reload_stats, sizeof(remote_reload_stats)); + + curr_net = devlink_net(devlink); + devlink_ns_change_notify(devlink, dest_net, curr_net, false); err = devlink->ops->reload_down(devlink, !!dest_net, action, limit, extack); if (err) return err;
- if (dest_net && !net_eq(dest_net, devlink_net(devlink))) - devlink_reload_netns_change(devlink, dest_net); + if (dest_net && !net_eq(dest_net, curr_net)) + __devlink_net_set(devlink, dest_net);
err = devlink->ops->reload_up(devlink, action, limit, actions_performed, extack); devlink_reload_failed_set(devlink, !!err); if (err) return err;
+ devlink_ns_change_notify(devlink, dest_net, curr_net, true); WARN_ON(!(*actions_performed & BIT(action))); /* Catch driver on updating the remote action within devlink reload */ WARN_ON(memcmp(remote_reload_stats, devlink->stats.remote_reload_stats,