kernel/linux.git/net/bridge/br_input.c, branch v5.10.257

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled

2026-04-18T08:30:52+00:00

[ Upstream commit e5e890630533bdc15b26a34bb8e7ef539bdf1322 ] When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled. Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports") Reported-by: Guruprasad C P Closes: https://lore.kernel.org/netdev/CAHXs0ORzd62QOG-Fttqa2Cx_A_VFp=utE2H2VTX5nqfgs7LDxQ@mail.gmail.com/ Signed-off-by: Fernando Fernandez Mancera Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260304120357.9778-1-fmancera@suse.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: bridge: fix static key check

2026-02-06T15:40:11+00:00

[ Upstream commit cc0cf10fdaeadf5542d64a55b5b4120d3df90b7d ] Fix the check if netfilter's static keys are available. netfilter defines and exports static keys if CONFIG_JUMP_LABEL is enabled. (HAVE_JUMP_LABEL is never defined.) Fixes: 971502d77faa ("bridge: netfilter: unroll NF_HOOK helper in bridge input path") Signed-off-by: Martin Kaiser Reviewed-by: Florian Westphal Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260127101925.1754425-1-martin@kaiser.cx Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: bridge: use DEV_STATS_INC()

2023-10-10T19:53:28+00:00

[ Upstream commit 44bdb313da57322c9b3c108eb66981c6ec6509f4 ] syzbot/KCSAN reported data-races in br_handle_frame_finish() [1] This function can run from multiple cpus without mutual exclusion. Adopt SMP safe DEV_STATS_INC() to update dev->stats fields. Handles updates to dev->stats.tx_dropped while we are at it. [1] BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 1: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 run_ksoftirqd+0x17/0x20 kernel/softirq.c:921 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 0: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 do_softirq+0x5e/0x90 kernel/softirq.c:454 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x1a8/0x1f0 net/batman-adv/translation-table.c:1356 batadv_tt_purge+0x2b/0x630 net/batman-adv/translation-table.c:3560 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00000000000d7190 -> 0x00000000000d7191 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 14848 Comm: kworker/u4:11 Not tainted 6.6.0-rc1-syzkaller-00236-gad8a69f361b9 #0 Fixes: 1c29fc4989bc ("[BRIDGE]: keep track of received multicast packets") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Roopa Prabhu Cc: Nikolay Aleksandrov Cc: bridge@lists.linux-foundation.org Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20230918091351.1356153-1-edumazet@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: bridge: Clear offload_fwd_mark when passing frame up bridge interface.

2022-05-25T07:17:59+00:00

[ Upstream commit fbb3abdf2223cd0dfc07de85fe5a43ba7f435bdf ] It is possible to stack bridges on top of each other. Consider the following which makes use of an Ethernet switch: br1 / \ / \ / \ br0.11 wlan0 | br0 / | \ p1 p2 p3 br0 is offloaded to the switch. Above br0 is a vlan interface, for vlan 11. This vlan interface is then a slave of br1. br1 also has a wireless interface as a slave. This setup trunks wireless lan traffic over the copper network inside a VLAN. A frame received on p1 which is passed up to the bridge has the skb->offload_fwd_mark flag set to true, indicating that the switch has dealt with forwarding the frame out ports p2 and p3 as needed. This flag instructs the software bridge it does not need to pass the frame back down again. However, the flag is not getting reset when the frame is passed upwards. As a result br1 sees the flag, wrongly interprets it, and fails to forward the frame to wlan0. When passing a frame upwards, clear the flag. This is the Rx equivalent of br_switchdev_frame_unmark() in br_dev_xmit(). Fixes: f1c2eddf4cb6 ("bridge: switchdev: Use an helper to clear forward mark") Signed-off-by: Andrew Lunn Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20220518005840.771575-1-andrew@lunn.ch Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: bridge: allow enslaving some DSA master network devices

2020-05-11T02:52:33+00:00

Commit 8db0a2ee2c63 ("net: bridge: reject DSA-enabled master netdevices as bridge members") added a special check in br_if.c in order to check for a DSA master network device with a tagging protocol configured. This was done because back then, such devices, once enslaved in a bridge would become inoperative and would not pass DSA tagged traffic anymore due to br_handle_frame returning RX_HANDLER_CONSUMED. But right now we have valid use cases which do require bridging of DSA masters. One such example is when the DSA master ports are DSA switch ports themselves (in a disjoint tree setup). This should be completely equivalent, functionally speaking, from having multiple DSA switches hanging off of the ports of a switchdev driver. So we should allow the enslaving of DSA tagged master network devices. Instead of the regular br_handle_frame(), install a new function br_handle_frame_dummy() on these DSA masters, which returns RX_HANDLER_PASS in order to call into the DSA specific tagging protocol handlers, and lift the restriction from br_add_if. Suggested-by: Nikolay Aleksandrov Suggested-by: Florian Fainelli Signed-off-by: Vladimir Oltean Acked-by: Nikolay Aleksandrov Reviewed-by: Florian Fainelli Tested-by: Florian Fainelli Signed-off-by: Jakub Kicinski

bridge: mrp: Integrate MRP into the bridge

2020-04-27T18:40:25+00:00

To integrate MRP into the bridge, the bridge needs to do the following: - detect if the MRP frame was received on MRP ring port in that case it would be processed otherwise just forward it as usual. - enable parsing of MRP - before whenever the bridge was set up, it would set all the ports in forwarding state. Add an extra check to not set ports in forwarding state if the port is an MRP ring port. The reason of this change is that if the MRP instance initially sets the port in blocked state by setting the bridge up it would overwrite this setting. Reviewed-by: Nikolay Aleksandrov Signed-off-by: Horatiu Vultur Signed-off-by: David S. Miller

net: bridge: vlan: add per-vlan state

2020-01-24T11:58:14+00:00

The first per-vlan option added is state, it is needed for EVPN and for per-vlan STP. The state allows to control the forwarding on per-vlan basis. The vlan state is considered only if the port state is forwarding in order to avoid conflicts and be consistent. br_allowed_egress is called only when the state is forwarding, but the ingress case is a bit more complicated due to the fact that we may have the transition between port:BR_STATE_FORWARDING -> vlan:BR_STATE_LEARNING which should still allow the bridge to learn from the packet after vlan filtering and it will be dropped after that. Also to optimize the pvid state check we keep a copy in the vlan group to avoid one lookup. The state members are modified with *_ONCE() to annotate the lockless access. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: fdb: eliminate extra port state tests from fast-path

2019-11-04T19:15:27+00:00

When commit df1c0b8468b3 ("[BRIDGE]: Packets leaking out of disabled/blocked ports.") introduced the port state tests in br_fdb_update() it was to avoid learning/refreshing from STP BPDUs, it was also used to avoid learning/refreshing from user-space with NTF_USE. Those two tests are done for every packet entering the bridge if it's learning, but for the fast-path we already have them checked in br_handle_frame() and is unnecessary to do it again. Thus push the checks to the unlikely cases and drop them from br_fdb_update(), the new nbp_state_should_learn() helper is used to determine if the port state allows br_fdb_update() to be called. The two places which need to do it manually are: - user-space add call with NTF_USE set - link-local packet learning done in __br_handle_local_finish() Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: fdb: br_fdb_update can take flags directly

2019-11-01T17:32:43+00:00

If we modify br_fdb_update() to take flags directly we can get rid of one test and one atomic bitop in the learning path. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: fdb: convert is_local to bitops

2019-10-30T01:12:49+00:00

The patch adds a new fdb flags field in the hole between the two cache lines and uses it to convert is_local to bitops. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller