================================================================== BUG: KCSAN: data-race in __mod_timer / expire_timers write to 0xffff88813bc1b908 of 8 bytes by interrupt on cpu 0: expire_timers+0x11e/0x260 kernel/time/timer.c:1477 __run_timers+0x358/0x3f0 kernel/time/timer.c:1745 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1758 __do_softirq+0x13c/0x2c3 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu+0xb4/0xc0 kernel/softirq.c:422 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 smap_restore arch/x86/include/asm/smap.h:71 [inline] kcsan_setup_watchpoint+0x436/0x470 kernel/kcsan/core.c:590 zap_pte_range+0x22a/0x13f0 mm/memory.c:1261 zap_pmd_range mm/memory.c:1380 [inline] zap_pud_range mm/memory.c:1409 [inline] zap_p4d_range mm/memory.c:1430 [inline] unmap_page_range+0x540/0x650 mm/memory.c:1451 unmap_single_vma+0x157/0x210 mm/memory.c:1496 unmap_vmas+0xc0/0x170 mm/memory.c:1528 exit_mmap+0x1be/0x400 mm/mmap.c:3218 __mmput+0xa2/0x220 kernel/fork.c:1082 mmput+0x3d/0x50 kernel/fork.c:1103 exit_mm+0x344/0x430 kernel/exit.c:501 do_exit+0x3ff/0x1670 kernel/exit.c:812 do_group_exit+0xa4/0x180 kernel/exit.c:922 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88813bc1b908 of 8 bytes by task 3135 on cpu 1: __mod_timer+0x44e/0xc10 kernel/time/timer.c:1035 add_timer+0x38/0x50 kernel/time/timer.c:1142 __queue_delayed_work+0xec/0x150 kernel/workqueue.c:1655 queue_delayed_work_on+0x6f/0xd0 kernel/workqueue.c:1680 queue_delayed_work include/linux/workqueue.h:522 [inline] wb_wakeup_delayed+0x95/0xb0 mm/backing-dev.c:270 wb_workfn+0x2ad/0x430 fs/fs-writeback.c:2108 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x616/0xa70 kernel/workqueue.c:2421 kthread+0x20b/0x230 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 3135 Comm: kworker/u4:4 Not tainted 5.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-8:0) ==================================================================