bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
==================================================================
BUG: KCSAN: data-race in br_fdb_update / br_fdb_update

read to 0xffff8881022ad1c0 of 8 bytes by interrupt on cpu 0:
 br_fdb_update+0x10e/0x480 net/bridge/br_fdb.c:903
 br_handle_frame_finish+0x338/0xe90 net/bridge/br_input.c:144
 br_nf_hook_thresh+0x1e5/0x220
 br_nf_pre_routing_finish_ipv6+0x575/0x5a0
 NF_HOOK include/linux/netfilter.h:314 [inline]
 br_nf_pre_routing_ipv6+0x1f6/0x2a0 net/bridge/br_netfilter_ipv6.c:184
 br_nf_pre_routing+0x517/0xbc0 net/bridge/br_netfilter_hooks.c:508
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:282 [inline]
 br_handle_frame+0x4e0/0x9b0 net/bridge/br_input.c:433
 __netif_receive_skb_core+0xb1a/0x2350 net/core/dev.c:5787
 __netif_receive_skb_one_core net/core/dev.c:5891 [inline]
 __netif_receive_skb+0x5a/0x280 net/core/dev.c:6006
 process_backlog+0x22e/0x440 net/core/dev.c:6354
 __napi_poll+0x63/0x3c0 net/core/dev.c:7188
 napi_poll net/core/dev.c:7257 [inline]
 net_rx_action+0x3a1/0x7f0 net/core/dev.c:7379
 handle_softirqs+0xbf/0x280 kernel/softirq.c:561
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:950
 smpboot_thread_fn+0x31c/0x4c0 kernel/smpboot.c:164
 kthread+0x4ae/0x520 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

write to 0xffff8881022ad1c0 of 8 bytes by interrupt on cpu 1:
 br_fdb_update+0x142/0x480 net/bridge/br_fdb.c:904
 br_handle_frame_finish+0x338/0xe90 net/bridge/br_input.c:144
 br_nf_hook_thresh+0x1e5/0x220
 br_nf_pre_routing_finish_ipv6+0x575/0x5a0
 NF_HOOK include/linux/netfilter.h:314 [inline]
 br_nf_pre_routing_ipv6+0x1f6/0x2a0 net/bridge/br_netfilter_ipv6.c:184
 br_nf_pre_routing+0x517/0xbc0 net/bridge/br_netfilter_hooks.c:508
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:282 [inline]
 br_handle_frame+0x4e0/0x9b0 net/bridge/br_input.c:433
 __netif_receive_skb_core+0xb1a/0x2350 net/core/dev.c:5787
 __netif_receive_skb_one_core net/core/dev.c:5891 [inline]
 __netif_receive_skb+0x5a/0x280 net/core/dev.c:6006
 process_backlog+0x22e/0x440 net/core/dev.c:6354
 __napi_poll+0x63/0x3c0 net/core/dev.c:7188
 napi_poll net/core/dev.c:7257 [inline]
 net_rx_action+0x3a1/0x7f0 net/core/dev.c:7379
 handle_softirqs+0xbf/0x280 kernel/softirq.c:561
 do_softirq+0x5e/0x90 kernel/softirq.c:462
 __local_bh_enable_ip+0x6e/0x70 kernel/softirq.c:389
 __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]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x522/0x620 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4db/0xa20 kernel/workqueue.c:3319
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3400
 kthread+0x4ae/0x520 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x000000010000002d -> 0x000000010000002e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 37 Comm: kworker/u8:2 Tainted: G        W          6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
net_ratelimit: 20966 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
net_ratelimit: 21747 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)