==================================================================
BUG: KCSAN: data-race in br_fdb_update / br_fdb_update

read to 0xffff88810556cbc0 of 8 bytes by interrupt on cpu 1:
 br_fdb_update+0x106/0x460 net/bridge/br_fdb.c:1005
 br_handle_frame_finish+0x34b/0x1040 net/bridge/br_input.c:144
 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline]
 br_handle_frame+0x5d1/0x9e0 net/bridge/br_input.c:442
 __netif_receive_skb_core+0xad3/0x2550 net/core/dev.c:5966
 __netif_receive_skb_one_core net/core/dev.c:6077 [inline]
 __netif_receive_skb+0x59/0x270 net/core/dev.c:6192
 process_backlog+0x229/0x420 net/core/dev.c:6544
 __napi_poll+0x66/0x310 net/core/dev.c:7594
 napi_poll net/core/dev.c:7657 [inline]
 net_rx_action+0x423/0x8c0 net/core/dev.c:7784
 handle_softirqs+0xba/0x290 kernel/softirq.c:622
 do_softirq+0x5d/0x90 kernel/softirq.c:523
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450
 __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]
 release_sock+0x116/0x150 net/core/sock.c:3744
 rds_tcp_tune+0x263/0x2a0 net/rds/tcp.c:-1
 rds_tcp_conn_path_connect+0x1a0/0x440 net/rds/tcp_connect.c:127
 rds_connect_worker+0x12f/0x1b0 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

write to 0xffff88810556cbc0 of 8 bytes by interrupt on cpu 0:
 br_fdb_update+0x13e/0x460 net/bridge/br_fdb.c:1006
 br_handle_frame_finish+0x34b/0x1040 net/bridge/br_input.c:144
 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline]
 br_handle_frame+0x5d1/0x9e0 net/bridge/br_input.c:442
 __netif_receive_skb_core+0xad3/0x2550 net/core/dev.c:5966
 __netif_receive_skb_one_core net/core/dev.c:6077 [inline]
 __netif_receive_skb+0x59/0x270 net/core/dev.c:6192
 process_backlog+0x229/0x420 net/core/dev.c:6544
 __napi_poll+0x66/0x310 net/core/dev.c:7594
 napi_poll net/core/dev.c:7657 [inline]
 net_rx_action+0x423/0x8c0 net/core/dev.c:7784
 handle_softirqs+0xba/0x290 kernel/softirq.c:622
 do_softirq+0x5d/0x90 kernel/softirq.c:523
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450
 __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_global_purge net/batman-adv/translation-table.c:2250 [inline]
 batadv_tt_purge+0x2cd/0x610 net/batman-adv/translation-table.c:3510
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000100010577 -> 0x0000000100010578

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13795 Comm: kworker/u8:9 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_tt_purge
==================================================================