linux/net/bridge
Nikolay Aleksandrov cfc579f9d8 net: bridge: fix vlan tunnel dst refcnt when egressing
The egress tunnel code uses dst_clone() and directly sets the result
which is wrong because the entry might have 0 refcnt or be already deleted,
causing number of problems. It also triggers the WARN_ON() in dst_hold()[1]
when a refcnt couldn't be taken. Fix it by using dst_hold_safe() and
checking if a reference was actually taken before setting the dst.

[1] dmesg WARN_ON log and following refcnt errors
 WARNING: CPU: 5 PID: 38 at include/net/dst.h:230 br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Modules linked in: 8021q garp mrp bridge stp llc bonding ipv6 virtio_net
 CPU: 5 PID: 38 Comm: ksoftirqd/5 Kdump: loaded Tainted: G        W         5.13.0-rc3+ #360
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
 RIP: 0010:br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Code: e8 85 bc 01 e1 45 84 f6 74 90 45 31 f6 85 db 48 c7 c7 a0 02 19 a0 41 0f 94 c6 31 c9 31 d2 44 89 f6 e8 64 bc 01 e1 85 db 75 02 <0f> 0b 31 c9 31 d2 44 89 f6 48 c7 c7 70 02 19 a0 e8 4b bc 01 e1 49
 RSP: 0018:ffff8881003d39e8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa01902a0
 RBP: ffff8881040c6700 R08: 0000000000000000 R09: 0000000000000001
 R10: 2ce93d0054fe0d00 R11: 54fe0d00000e0000 R12: ffff888109515000
 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000401
 FS:  0000000000000000(0000) GS:ffff88822bf40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f42ba70f030 CR3: 0000000109926000 CR4: 00000000000006e0
 Call Trace:
  br_handle_vlan+0xbc/0xca [bridge]
  __br_forward+0x23/0x164 [bridge]
  deliver_clone+0x41/0x48 [bridge]
  br_handle_frame_finish+0x36f/0x3aa [bridge]
  ? skb_dst+0x2e/0x38 [bridge]
  ? br_handle_ingress_vlan_tunnel+0x3e/0x1c8 [bridge]
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  br_handle_frame+0x2c3/0x377 [bridge]
  ? __skb_pull+0x33/0x51
  ? vlan_do_receive+0x4f/0x36a
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  __netif_receive_skb_core+0x539/0x7c6
  ? __list_del_entry_valid+0x16e/0x1c2
  __netif_receive_skb_list_core+0x6d/0xd6
  netif_receive_skb_list_internal+0x1d9/0x1fa
  gro_normal_list+0x22/0x3e
  dev_gro_receive+0x55b/0x600
  ? detach_buf_split+0x58/0x140
  napi_gro_receive+0x94/0x12e
  virtnet_poll+0x15d/0x315 [virtio_net]
  __napi_poll+0x2c/0x1c9
  net_rx_action+0xe6/0x1fb
  __do_softirq+0x115/0x2d8
  run_ksoftirqd+0x18/0x20
  smpboot_thread_fn+0x183/0x19c
  ? smpboot_unregister_percpu_thread+0x66/0x66
  kthread+0x10a/0x10f
  ? kthread_mod_delayed_work+0xb6/0xb6
  ret_from_fork+0x22/0x30
 ---[ end trace 49f61b07f775fd2b ]---
 dst_release: dst:00000000c02d677a refcnt:-1
 dst_release underflow

Cc: stable@vger.kernel.org
Fixes: 11538d039a ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-10 14:06:43 -07:00
..
netfilter netfilter: allow to turn off xtables compat layer 2021-04-26 18:16:56 +02:00
br_arp_nd_proxy.c net: bridge: when suppression is enabled exclude RARP packets 2021-03-22 13:30:24 -07:00
br_cfm_netlink.c bridge: cfm: Netlink Notifications. 2020-10-29 18:39:44 -07:00
br_cfm.c bridge: cfm: Netlink Notifications. 2020-10-29 18:39:44 -07:00
br_device.c netfilter: flowtable: bridge vlan hardware offload and switchdev 2021-03-24 12:48:39 -07:00
br_fdb.c net: bridge: add helper to replay port and local fdb entries 2021-03-23 14:49:05 -07:00
br_forward.c net: bridge: check vlan with eth_type_vlan() method 2021-01-18 14:27:33 -08:00
br_if.c bridge: cfm: Kernel space implementation of CFM. MEP create/delete. 2020-10-29 18:39:43 -07:00
br_input.c net: bridge: Fix fall-through warnings for Clang 2021-03-10 12:45:15 -08:00
br_ioctl.c net: bridge: delete duplicated words 2020-09-18 14:12:43 -07:00
br_mdb.c net: bridge: add helper to replay port and host-joined mdb entries 2021-03-23 14:49:05 -07:00
br_mrp_netlink.c bridge: mrp: Use hlist_head instead of list_head for mrp 2020-11-09 16:42:12 -08:00
br_mrp_switchdev.c bridge: mrp: Extend br_mrp_switchdev to detect better the errors 2021-02-16 14:47:46 -08:00
br_mrp.c bridge: mrp: Disable roles before deleting the MRP instance 2021-03-24 12:14:08 -07:00
br_multicast_eht.c net: bridge: mcast: factor out common allow/block EHT handling 2021-03-16 11:57:57 -07:00
br_multicast.c net: bridge: mcast: fix broken length + header check for MRDv6 Adv. 2021-04-27 14:02:06 -07:00
br_netfilter_hooks.c netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal 2020-11-28 11:46:51 -08:00
br_netfilter_ipv6.c
br_netlink_tunnel.c net: bridge: notify on vlan tunnel changes done via the old api 2020-07-12 15:18:24 -07:00
br_netlink.c bridge: Fix possible races between assigning rx_handler_data and setting IFF_BRIDGE_PORT bit 2021-04-29 15:33:17 -07:00
br_nf_core.c
br_private_cfm.h bridge: cfm: Kernel space implementation of CFM. CCM frame RX added. 2020-10-29 18:39:43 -07:00
br_private_mcast_eht.h net: bridge: multicast: make tracked EHT hosts limit configurable 2021-01-27 17:40:35 -08:00
br_private_mrp.h bridge: mrp: Extend br_mrp_switchdev to detect better the errors 2021-02-16 14:47:46 -08:00
br_private_stp.h
br_private_tunnel.h
br_private.h net: bridge: fix vlan tunnel dst null pointer dereference 2021-06-10 14:06:43 -07:00
br_stp_bpdu.c
br_stp_if.c
br_stp_timer.c
br_stp.c net: bridge: add helper to retrieve the current ageing time 2021-03-23 14:49:05 -07:00
br_switchdev.c net: bridge: switchdev: include local flag in FDB notifications 2021-04-16 15:15:45 -07:00
br_sysfs_br.c net: bridge: propagate error code and extack from br_mc_disabled_update 2021-04-14 14:32:05 -07:00
br_sysfs_if.c net: bridge: don't print in br_switchdev_set_port_flag 2021-02-12 17:08:04 -08:00
br_vlan_options.c
br_vlan_tunnel.c net: bridge: fix vlan tunnel dst refcnt when egressing 2021-06-10 14:06:43 -07:00
br_vlan.c netfilter: flowtable: bridge vlan hardware offload and switchdev 2021-03-24 12:48:39 -07:00
br.c net: bridge: fix misspellings using codespell tool 2021-01-09 13:54:47 -08:00
Kconfig bridge: cfm: Add BRIDGE_CFM to Kconfig. 2020-10-29 18:39:43 -07:00
Makefile net: bridge: multicast: add EHT host handling functions 2021-01-22 19:39:56 -08:00