================================================================== 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:1474 sched_tick+0xd2/0x110 kernel/sched/core.c:5609 update_process_times+0x15a/0x180 kernel/time/timer.c:2524 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:1691 [inline] __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 tty_ldisc_receive_buf+0x2c/0x100 drivers/tty/tty_buffer.c:386 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:3229 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 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:1474 sched_tick+0xd2/0x110 kernel/sched/core.c:5609 update_process_times+0x15a/0x180 kernel/time/timer.c:2524 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:1691 [inline] __hrtimer_run_queues+0x20d/0x5e0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 is_atomic kernel/kcsan/core.c:249 [inline] should_watch kernel/kcsan/core.c:277 [inline] check_access kernel/kcsan/core.c:752 [inline] __tsan_read8+0xe5/0x180 kernel/kcsan/core.c:1025 tty_put_char+0x3f/0xc0 drivers/tty/tty_io.c:3166 n_tty_process_echo_ops drivers/tty/n_tty.c:663 [inline] __process_echoes+0x393/0x6b0 drivers/tty/n_tty.c:709 commit_echoes drivers/tty/n_tty.c:772 [inline] n_tty_receive_char+0x608/0x680 drivers/tty/n_tty.c:1437 n_tty_receive_buf_standard+0x4bd/0x2e30 drivers/tty/n_tty.c:1606 __receive_buf drivers/tty/n_tty.c:1640 [inline] n_tty_receive_buf_common+0x83a/0xbe0 drivers/tty/n_tty.c:1739 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:3229 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 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: 0x000000000014c080 -> 0x000000000014e790 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 4198 Comm: kworker/u8:20 Tainted: G W 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound flush_to_ldisc ==================================================================