syzbot


KCSAN: data-race in hrtimer_reprogram / print_cpu (8)

Status: auto-obsoleted due to no activity on 2023/12/26 20:48
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+a717c11dbd302d767fe5@syzkaller.appspotmail.com
First crash: 239d, last: 239d
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 6 18d 37d 0/27 moderation: reported on 2024/06/11 09:00
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (9) kernel 7 129d 184d 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 362d 547d 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 1581d 1581d 0/27 auto-closed as invalid on 2020/05/29 16:43
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (2) kernel 1 1414d 1414d 0/27 auto-closed as invalid on 2020/10/08 05:09
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (5) kernel 11 641d 724d 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 984d 984d 0/27 auto-closed as invalid on 2021/12/12 15:07
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (10) kernel 2 82d 83d 0/27 auto-obsoleted due to no activity on 2024/06/01 18:17
upstream KCSAN: data-race in hrtimer_reprogram / print_cpu (7) kernel 3 316d 326d 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 948d 948d 0/27 auto-closed as invalid on 2022/01/17 18:45

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

write to 0xffff888237c1ede0 of 8 bytes by task 3072 on cpu 0:
 __hrtimer_reprogram kernel/time/hrtimer.c:661 [inline]
 hrtimer_reprogram+0x1a8/0x220 kernel/time/hrtimer.c:868
 hrtimer_start_range_ns+0x4e3/0x660 kernel/time/hrtimer.c:1302
 hrtimer_start_expires include/linux/hrtimer.h:432 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1968 [inline]
 do_nanosleep+0x85/0x2f0 kernel/time/hrtimer.c:2044
 hrtimer_nanosleep kernel/time/hrtimer.c:2100 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:2135 [inline]
 __se_sys_nanosleep+0x20b/0x2e0 kernel/time/hrtimer.c:2121
 __x64_sys_nanosleep+0x31/0x40 kernel/time/hrtimer.c:2121
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888237c1ede0 of 8 bytes by task 21370 on cpu 1:
 print_cpu+0x2fb/0x640 kernel/time/timer_list.c:133
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x612/0x8f0 fs/seq_file.c:272
 proc_reg_read_iter+0x114/0x180 fs/proc/inode.c:302
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:993 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x000002adb4c1b79e -> 0x000002adb4b78b54

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21370 Comm: syz-executor.3 Not tainted 6.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/21 20:47 upstream 98b1cc82c4af cb976f63 .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.