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BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick

read-write to 0xffff88810006ceb8 of 8 bytes by interrupt on cpu 1:
 wq_worker_tick+0x63/0x240 kernel/workqueue.c:1476
 sched_tick+0xd2/0x110 kernel/sched/core.c:5481
 update_process_times+0x15a/0x180 kernel/time/timer.c:2490
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1049
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 check_access kernel/kcsan/core.c:747 [inline]
 __tsan_read8+0xb3/0x180 kernel/kcsan/core.c:1025
 n_tty_receive_buf_common+0x1d9/0xbe0 drivers/tty/n_tty.c:1725
 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1785
 tty_ldisc_receive_buf+0x63/0x100 drivers/tty/tty_buffer.c:387
 tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x1ce/0x410 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3393
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read-write to 0xffff88810006ceb8 of 8 bytes by interrupt on cpu 0:
 wq_worker_tick+0x63/0x240 kernel/workqueue.c:1476
 sched_tick+0xd2/0x110 kernel/sched/core.c:5481
 update_process_times+0x15a/0x180 kernel/time/timer.c:2490
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1049
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x3d/0x60 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 pcpu_alloc_noprof+0x77a/0x10c0 mm/percpu.c:1867
 fib6_nh_init+0x63a/0x15d0 net/ipv6/route.c:3628
 ip6_route_info_create+0x7b2/0xba0 net/ipv6/route.c:3809
 ip6_route_add+0x26/0x120 net/ipv6/route.c:3853
 addrconf_prefix_route net/ipv6/addrconf.c:2486 [inline]
 addrconf_add_linklocal+0x29c/0x390 net/ipv6/addrconf.c:3319
 addrconf_addr_gen+0x278/0x450 net/ipv6/addrconf.c:3448
 addrconf_init_auto_addrs+0x586/0x6b0
 addrconf_notify+0x7ae/0x950 net/ipv6/addrconf.c:3745
 notifier_call_chain kernel/notifier.c:93 [inline]
 raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:461
 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:1996
 netdev_state_change+0x80/0xc0 net/core/dev.c:1378
 linkwatch_do_dev+0xb9/0xf0 net/core/link_watch.c:177
 __linkwatch_run_queue+0x284/0x510 net/core/link_watch.c:234
 linkwatch_event+0x40/0x50 net/core/link_watch.c:277
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3393
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x0000000000bd0e70 -> 0x0000000000bd3580

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7832 Comm: kworker/u8:17 Not tainted 6.11.0-syzkaller-02520-gadfc3ded5c33 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events_unbound linkwatch_event
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