syzbot

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BUG: KCSAN: data-race in batadv_tt_local_add / batadv_tt_local_add

write to 0xffff888118c739c0 of 8 bytes by interrupt on cpu 1:
 batadv_tt_local_add+0x176/0xfe0 net/batman-adv/translation-table.c:619
 batadv_interface_tx+0x442/0xb30 net/batman-adv/mesh-interface.c:236
 __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
 netdev_start_xmit include/linux/netdevice.h:5224 [inline]
 xmit_one net/core/dev.c:3830 [inline]
 dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3846
 __dev_queue_xmit+0x10b9/0x1fb0 net/core/dev.c:4713
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 br_dev_queue_push_xmit+0x42d/0x4e0 net/bridge/br_forward.c:53
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_forward_finish+0x89/0x160 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline]
 br_nf_forward_finish+0x6c1/0x740 net/bridge/br_netfilter_hooks.c:665
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_nf_forward_arp net/bridge/br_netfilter_hooks.c:755 [inline]
 br_nf_forward+0xae3/0xe90 net/bridge/br_netfilter_hooks.c:778
 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
 nf_hook_slow+0x75/0x180 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:272 [inline]
 NF_HOOK include/linux/netfilter.h:315 [inline]
 __br_forward+0x275/0x350 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0x1ae/0x250 net/bridge/br_forward.c:190
 br_flood+0x21f/0x460 net/bridge/br_forward.c:237
 br_handle_frame_finish+0xdd3/0xf50 net/bridge/br_input.c:221
 nf_hook_bridge_pre net/bridge/br_input.c:305 [inline]
 br_handle_frame+0x5d1/0x9e0 net/bridge/br_input.c:434
 __netif_receive_skb_core+0xaad/0x2410 net/core/dev.c:5863
 __netif_receive_skb_one_core net/core/dev.c:5975 [inline]
 __netif_receive_skb+0x59/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:164
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

write to 0xffff888118c739c0 of 8 bytes by interrupt on cpu 0:
 batadv_tt_local_add+0x176/0xfe0 net/batman-adv/translation-table.c:619
 batadv_interface_tx+0x442/0xb30 net/batman-adv/mesh-interface.c:236
 __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
 netdev_start_xmit include/linux/netdevice.h:5224 [inline]
 xmit_one net/core/dev.c:3830 [inline]
 dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3846
 __dev_queue_xmit+0x10b9/0x1fb0 net/core/dev.c:4713
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 br_dev_queue_push_xmit+0x42d/0x4e0 net/bridge/br_forward.c:53
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_forward_finish+0x89/0x160 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline]
 br_nf_forward_finish+0x6c1/0x740 net/bridge/br_netfilter_hooks.c:665
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_nf_forward_arp net/bridge/br_netfilter_hooks.c:755 [inline]
 br_nf_forward+0xae3/0xe90 net/bridge/br_netfilter_hooks.c:778
 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
 nf_hook_slow+0x75/0x180 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:272 [inline]
 NF_HOOK include/linux/netfilter.h:315 [inline]
 __br_forward+0x275/0x350 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0x1ae/0x250 net/bridge/br_forward.c:190
 br_flood+0x21f/0x460 net/bridge/br_forward.c:237
 br_handle_frame_finish+0xdd3/0xf50 net/bridge/br_input.c:221
 nf_hook_bridge_pre net/bridge/br_input.c:305 [inline]
 br_handle_frame+0x5d1/0x9e0 net/bridge/br_input.c:434
 __netif_receive_skb_core+0xaad/0x2410 net/core/dev.c:5863
 __netif_receive_skb_one_core net/core/dev.c:5975 [inline]
 __netif_receive_skb+0x59/0x270 net/core/dev.c:6090
 process_backlog+0x229/0x420 net/core/dev.c:6442
 __napi_poll+0x63/0x3a0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x391/0x830 net/core/dev.c:7605
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 do_softirq+0x5d/0x90 kernel/softirq.c:480
 __local_bh_enable_ip+0x70/0x80 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_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:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000ffffed78 -> 0x00000000ffffed79

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 399 Comm: kworker/u8:6 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_tt_purge
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