syzbot


KCSAN: data-race in clockevents_program_event / print_tickdevice (4)

Status: auto-closed as invalid on 2022/03/19 14:36
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 293d, last: 293d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (5) 7 144d 170d 0/24 auto-closed as invalid on 2022/08/15 19:00
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (2) 1 505d 505d 0/24 auto-closed as invalid on 2021/08/19 20:40
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice 1 589d 585d 0/24 auto-closed as invalid on 2021/05/28 09:07
upstream KCSAN: data-race in clockevents_program_event / print_tickdevice (3) 5 395d 425d 0/24 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 0xffff888237d1af18 of 8 bytes by task 1798 on cpu 1:
 clockevents_program_event+0x35/0x1e0 kernel/time/clockevents.c:313
 tick_program_event+0x84/0xd0 kernel/time/tick-oneshot.c:44
 __hrtimer_reprogram kernel/time/hrtimer.c:681 [inline]
 hrtimer_reprogram+0x211/0x250 kernel/time/hrtimer.c:866
 hrtimer_start_range_ns+0xf8/0x140 kernel/time/hrtimer.c:1299
 hrtimer_start_expires include/linux/hrtimer.h:432 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1965 [inline]
 do_nanosleep+0x97/0x3a0 kernel/time/hrtimer.c:2041
 hrtimer_nanosleep kernel/time/hrtimer.c:2097 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:2131 [inline]
 __se_sys_nanosleep+0x22e/0x2f0 kernel/time/hrtimer.c:2118
 __x64_sys_nanosleep+0x2d/0x40 kernel/time/hrtimer.c:2118
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237d1af18 of 8 bytes by task 11026 on cpu 0:
 print_tickdevice+0x158/0x370 kernel/time/timer_list.c:204
 timer_list_show+0x74/0x180 kernel/time/timer_list.c:296
 seq_read_iter+0x60b/0x930 fs/seq_file.c:272
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:300
 call_read_iter include/linux/fs.h:2068 [inline]
 generic_file_splice_read+0x24f/0x330 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+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000007fd91d4d8d -> 0x0000007fd91665ce

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11026 Comm: syz-executor.0 Not tainted 5.17.0-rc3-syzkaller-00247-g83e396641110-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/12 14:36 upstream 83e396641110 8b9ca619 .config log report info KCSAN: data-race in clockevents_program_event / print_tickdevice
* Struck through repros no longer work on HEAD.