================================================================== BUG: KCSAN: data-race in br_fdb_update / br_fdb_update write to 0xffff8881185217c0 of 8 bytes by interrupt on cpu 1: br_fdb_update+0x14e/0x4c0 net/bridge/br_fdb.c:904 br_handle_frame_finish+0x315/0xf70 net/bridge/br_input.c:144 nf_hook_bridge_pre net/bridge/br_input.c:304 [inline] br_handle_frame+0x5b6/0x9b0 net/bridge/br_input.c:433 __netif_receive_skb_core+0xaf6/0x2580 net/core/dev.c:5771 __netif_receive_skb_one_core net/core/dev.c:5883 [inline] __netif_receive_skb+0x5d/0x290 net/core/dev.c:5998 process_backlog+0x22e/0x440 net/core/dev.c:6350 __napi_poll+0x63/0x3c0 net/core/dev.c:7322 napi_poll net/core/dev.c:7386 [inline] net_rx_action+0x3a3/0x800 net/core/dev.c:7508 handle_softirqs+0xbf/0x280 kernel/softirq.c:579 do_softirq+0x62/0xa0 kernel/softirq.c:480 __local_bh_enable_ip+0x6e/0x70 kernel/softirq.c:407 __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_dat_purge net/batman-adv/distributed-arp-table.c:185 [inline] batadv_dat_purge+0x1e6/0x270 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319 worker_thread+0x52c/0x710 kernel/workqueue.c:3400 kthread+0x4b7/0x540 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffff8881185217c0 of 8 bytes by interrupt on cpu 0: br_fdb_update+0x119/0x4c0 net/bridge/br_fdb.c:903 br_handle_frame_finish+0x315/0xf70 net/bridge/br_input.c:144 nf_hook_bridge_pre net/bridge/br_input.c:304 [inline] br_handle_frame+0x5b6/0x9b0 net/bridge/br_input.c:433 __netif_receive_skb_core+0xaf6/0x2580 net/core/dev.c:5771 __netif_receive_skb_one_core net/core/dev.c:5883 [inline] __netif_receive_skb+0x5d/0x290 net/core/dev.c:5998 process_backlog+0x22e/0x440 net/core/dev.c:6350 __napi_poll+0x63/0x3c0 net/core/dev.c:7322 napi_poll net/core/dev.c:7386 [inline] net_rx_action+0x3a3/0x800 net/core/dev.c:7508 handle_softirqs+0xbf/0x280 kernel/softirq.c:579 do_softirq+0x62/0xa0 kernel/softirq.c:480 __local_bh_enable_ip+0x6e/0x70 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] fpu_clone+0x244/0x560 arch/x86/kernel/fpu/core.c:643 copy_thread+0x17d/0x390 arch/x86/kernel/process.c:220 copy_process+0xd95/0x1f60 kernel/fork.c:2438 kernel_clone+0x168/0x5d0 kernel/fork.c:2844 __do_sys_clone kernel/fork.c:2987 [inline] __se_sys_clone kernel/fork.c:2971 [inline] __x64_sys_clone+0xe9/0x120 kernel/fork.c:2971 x64_sys_call+0x2dc9/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000ffffae59 -> 0x00000000ffffae5a Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 5439 Comm: dhcpcd-run-hook Not tainted 6.15.0-rc1-syzkaller-00333-g5aaaedb0cb54 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 ================================================================== net_ratelimit: 32510 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, 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 veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, 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 veth0_to_bridge with own address as source address (addr:0e:61:13:99:de:d6, vlan:0)