syzbot


KCSAN: data-race in hrtimer_reprogram / print_cpu (10)

Status: auto-obsoleted due to no activity on 2024/06/01 18:17
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+27b6f0842a11090153fe@syzkaller.appspotmail.com
First crash: 56d, last: 55d
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (11) kernel 5 4d11h 11d 0/27 moderation: reported on 2024/06/11 09:00
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (9) kernel 7 103d 158d 0/27 auto-obsoleted due to no activity on 2024/04/14 23:48
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (6) kernel 19 335d 521d 0/27 auto-obsoleted due to no activity on 2023/08/26 13:01
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu kernel 1 1554d 1554d 0/27 auto-closed as invalid on 2020/05/29 16:43
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (2) kernel 1 1388d 1388d 0/27 auto-closed as invalid on 2020/10/08 05:09
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (5) kernel 11 614d 698d 0/27 auto-obsoleted due to no activity on 2022/11/20 13:25
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (3) kernel 1 957d 957d 0/27 auto-closed as invalid on 2021/12/12 15:07
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (7) kernel 3 289d 299d 0/27 auto-obsoleted due to no activity on 2023/10/11 12:54
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (4) kernel 1 921d 921d 0/27 auto-closed as invalid on 2022/01/17 18:45
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (8) kernel 1 213d 193d 0/27 auto-obsoleted due to no activity on 2023/12/26 20:48

Sample crash report:
==================================================================
BUG: KCSAN: data-race in hrtimer_reprogram / print_cpu

write to 0xffff888237d1ffa0 of 8 bytes by task 17639 on cpu 1:
 __hrtimer_reprogram kernel/time/hrtimer.c:662 [inline]
 hrtimer_reprogram+0x1a2/0x220 kernel/time/hrtimer.c:869
 hrtimer_start_range_ns+0x4ee/0x560 kernel/time/hrtimer.c:1306
 hrtimer_start_expires include/linux/hrtimer.h:289 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1972 [inline]
 do_nanosleep+0x86/0x300 kernel/time/hrtimer.c:2048
 hrtimer_nanosleep+0xe8/0x1e0 kernel/time/hrtimer.c:2104
 common_nsleep+0x68/0x90 kernel/time/posix-timers.c:1350
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline]
 __se_sys_clock_nanosleep+0x20a/0x240 kernel/time/posix-timers.c:1373
 __x64_sys_clock_nanosleep+0x55/0x70 kernel/time/posix-timers.c:1373
 x64_sys_call+0x2489/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:231
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d1ffa0 of 8 bytes by task 23867 on cpu 0:
 print_cpu+0x2fb/0x670 kernel/time/timer_list.c:133
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:295
 seq_read_iter+0x65b/0x940 fs/seq_file.c:272
 proc_reg_read_iter+0x11e/0x190 fs/proc/inode.c:299
 call_read_iter include/linux/fs.h:2104 [inline]
 copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x26c/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x970 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000009bca105980 -> 0x0000009bc9f0e012

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23867 Comm: syz-executor.2 Not tainted 6.9.0-rc5-syzkaller-00296-g5eb4573ea63d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/27 18:16 upstream 5eb4573ea63d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_reprogram / print_cpu
2024/04/26 11:31 upstream c942a0cd3603 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in hrtimer_reprogram / print_cpu
* Struck through repros no longer work on HEAD.