syzbot


KCSAN: data-race in hrtimer_interrupt / print_tickdevice (16)

Status: moderation: reported on 2026/02/09 15:15
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+fe1058f12ef7ca496af9@syzkaller.appspotmail.com
First crash: 103d, last: 14h29m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
058e6d8f-794d-47ca-a691-77776660c17e assessment-kcsan Benign: ✅ Confident: ✅ KCSAN: data-race in hrtimer_interrupt / print_tickdevice (16) 2026/02/25 03:30 2026/02/25 03:30 2026/02/25 03:32 305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
af9da953-4483-416b-91d0-ac34dacefcf6 assessment-kcsan 💥 KCSAN: data-race in hrtimer_interrupt / print_tickdevice (16) 2026/02/09 15:15 2026/02/09 15:15 2026/02/09 15:15 97745f52f5b9361548048f53f0b3b51b9313fedf fork/exec ./syz-agent: no such file or directory
Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (6) kernel 6 5 1400d 1424d 0/29 auto-closed as invalid on 2022/08/27 09:49
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (13) kernel 6 2 646d 652d 0/29 auto-obsoleted due to no activity on 2024/09/19 01:50
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (8) kernel 6 3 1271d 1295d 0/29 auto-obsoleted due to no activity on 2023/01/03 04:47
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (15) kernel 6 9 270d 468d 0/29 auto-obsoleted due to no activity on 2025/10/21 07:50
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (4) kernel 6 14 1536d 1701d 0/29 auto-closed as invalid on 2022/04/13 14:16
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (2) kernel 6 3 1837d 1841d 0/29 auto-closed as invalid on 2021/06/16 18:46
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (10) kernel 6 1 997d 997d 0/29 auto-obsoleted due to no activity on 2023/10/04 07:33
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (5) kernel 6 2 1473d 1473d 0/29 auto-closed as invalid on 2022/06/15 02:31
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (14) kernel 6 8 526d 596d 0/29 auto-obsoleted due to no activity on 2025/02/06 20:55
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (7) kernel 6 1 1344d 1344d 0/29 auto-obsoleted due to no activity on 2022/10/22 07:07
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (11) kernel 6 2 881d 894d 0/29 auto-obsoleted due to no activity on 2024/01/28 02:00
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (3) kernel 6 2 1751d 1786d 0/29 auto-closed as invalid on 2021/09/10 15:52
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice kernel 6 1 1952d 1952d 0/29 auto-closed as invalid on 2021/02/20 21:54
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (12) kernel 6 1 751d 751d 0/29 auto-obsoleted due to no activity on 2024/06/05 19:29
upstream KCSAN: data-race in hrtimer_interrupt / print_tickdevice (9) kernel 6 20 1063d 1212d 0/29 auto-obsoleted due to no activity on 2023/07/30 02:27

Sample crash report:
==================================================================
BUG: KCSAN: data-race in hrtimer_interrupt / print_tickdevice

write to 0xffff888237d17ba0 of 8 bytes by interrupt on cpu 1:
 hrtimer_interrupt+0x69/0x850 kernel/time/hrtimer.c:2092
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 __sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:233
 xas_next_entry include/linux/xarray.h:1736 [inline]
 next_uptodate_folio+0x172/0x7e0 mm/filemap.c:3705
 filemap_map_pages+0xa00/0xea0 mm/filemap.c:3940
 do_fault_around mm/memory.c:5867 [inline]
 do_read_fault mm/memory.c:5900 [inline]
 do_fault mm/memory.c:6043 [inline]
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6427 [inline]
 __handle_mm_fault mm/memory.c:6565 [inline]
 handle_mm_fault+0x1508/0x2e70 mm/memory.c:6734
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1290/0x1f10 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x242/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:4137 [inline]
 vm_mmap_pgoff+0x23b/0x2d0 mm/util.c:586
 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:606
 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d17ba0 of 8 bytes by task 6224 on cpu 0:
 print_tickdevice+0x142/0x340 kernel/time/timer_list.c:204
 timer_list_show+0x6c/0x170 kernel/time/timer_list.c:296
 seq_read_iter+0x636/0x940 fs/seq_file.c:273
 proc_reg_read_iter+0x110/0x180 fs/proc/inode.c:299
 copy_splice_read+0x471/0x6c0 fs/splice.c:362
 do_splice_read fs/splice.c:980 [inline]
 splice_direct_to_actor+0x26e/0x670 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000001e0bd33790 -> 0x0000001e0bfaba80

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6224 Comm: syz.2.871 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/23 04:21 upstream 79bd2dded182 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
2026/05/20 16:50 upstream df685633c3db 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
2026/05/03 12:59 upstream 66edb901bf87 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
2026/03/26 17:34 upstream 0138af2472df 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
2026/03/09 18:13 upstream 1f318b96cc84 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
2026/02/09 15:15 upstream 05f7e89ab973 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_interrupt / print_tickdevice
* Struck through repros no longer work on HEAD.