syzbot


KCSAN: data-race in clockevents_program_event / print_tickdevice

Status: auto-closed as invalid on 2021/05/28 09:07
Subsystems: kernel
[Documentation on labels]
First crash: 1070d, last: 1070d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (8) kernel 1 100d 100d 0/26 auto-obsoleted due to no activity on 2024/01/23 08:37
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (6) kernel 28 286d 578d 0/26 auto-obsoleted due to no activity on 2023/07/21 02:50
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (7) kernel 2 154d 154d 0/26 auto-obsoleted due to no activity on 2023/11/30 21:56
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (5) kernel 7 626d 652d 0/26 auto-closed as invalid on 2022/08/15 19:00
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (2) kernel 1 987d 987d 0/26 auto-closed as invalid on 2021/08/19 20:40
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (4) kernel 1 775d 775d 0/26 auto-closed as invalid on 2022/03/19 14:36
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (3) kernel 5 876d 907d 0/26 auto-closed as invalid on 2021/12/08 10:38

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

write to 0xffff888237c16ed8 of 8 bytes by interrupt on cpu 0:
 clockevents_program_event+0x35/0x1e0 kernel/time/clockevents.c:313
 tick_program_event+0x78/0xc0 kernel/time/tick-oneshot.c:44
 hrtimer_interrupt+0x895/0xaf0 kernel/time/hrtimer.c:1676
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
 check_kcov_mode kernel/kcov.c:165 [inline]
 __sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:197
 number+0x821/0xb50 lib/vsprintf.c:529
 vsnprintf+0xb6d/0xed0 lib/vsprintf.c:2717
 seq_vprintf+0x71/0xd0 fs/seq_file.c:395
 SEQ_printf+0x76/0xb0 kernel/time/timer_list.c:38
 print_timer kernel/time/timer_list.c:52 [inline]
 print_active_timers kernel/time/timer_list.c:91 [inline]
 print_base kernel/time/timer_list.c:112 [inline]
 print_cpu+0x2e5/0x690 kernel/time/timer_list.c:123
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:283
 seq_read_iter+0x60b/0x910 fs/seq_file.c:269
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:310
 call_read_iter include/linux/fs.h:1971 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237c16ed8 of 8 bytes by task 7741 on cpu 1:
 print_tickdevice+0x157/0x300 kernel/time/timer_list.c:204
 timer_list_show+0x74/0x180 kernel/time/timer_list.c:288
 seq_read_iter+0x60b/0x910 fs/seq_file.c:269
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:310
 call_read_iter include/linux/fs.h:1971 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7741 Comm: syz-executor.2 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/23 08:58 upstream 90c911ad7445 590921a5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in clockevents_program_event / print_tickdevice
* Struck through repros no longer work on HEAD.