syzbot


KCSAN: data-race in print_cpu / tick_irq_enter (2)

Status: auto-closed as invalid on 2022/09/11 23:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 120d, last: 120d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in print_cpu / tick_irq_enter 2 396d 427d 0/24 auto-closed as invalid on 2021/12/09 16:37
upstream KCSAN: data-race in print_cpu / tick_irq_enter (3) 1 65d 65d 0/24 auto-obsoleted due to no activity on 2022/11/06 07:20

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

read-write to 0xffff888237c1e100 of 8 bytes by interrupt on cpu 0:
 tick_nohz_stop_idle kernel/time/tick-sched.c:664 [inline]
 tick_nohz_irq_enter kernel/time/tick-sched.c:1429 [inline]
 tick_irq_enter+0x127/0x210 kernel/time/tick-sched.c:1455
 common_interrupt+0x8f/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x22/0x40
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:555 [inline]
 acpi_idle_enter+0x283/0x310 drivers/acpi/processor_idle.c:692
 cpuidle_enter_state+0x2ee/0x7a0 drivers/cpuidle/cpuidle.c:238
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:352
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x1b2/0x250 kernel/sched/idle.c:303
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400
 rest_init+0xe8/0xf0 init/main.c:727
 start_kernel+0x0/0x656 init/main.c:883
 start_kernel+0x5d1/0x656 init/main.c:1138
 secondary_startup_64_no_verify+0xcf/0xdb

read to 0xffff888237c1e100 of 8 bytes by task 9464 on cpu 1:
 print_cpu+0x56c/0x680 kernel/time/timer_list.c:161
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x676/0x8e0 fs/seq_file.c:272
 proc_reg_read_iter+0xfa/0x170 fs/proc/inode.c:305
 call_read_iter include/linux/fs.h:2183 [inline]
 generic_file_splice_read+0xe0/0x1c0 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x26c/0x620 fs/splice.c:868
 do_splice_direct+0xfb/0x180 fs/splice.c:977
 do_sendfile+0x3bf/0x910 fs/read_write.c:1251
 __do_sys_sendfile64 fs/read_write.c:1319 [inline]
 __se_sys_sendfile64 fs/read_write.c:1305 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1305
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x000000245bb882a6 -> 0x000000245bb8be47

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9464 Comm: syz-executor.2 Not tainted 5.19.0-syzkaller-12689-g3bc1bc0b59d0-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/08/07 23:14 upstream 3bc1bc0b59d0 88e3a122 .config log report info KCSAN: data-race in print_cpu / tick_irq_enter
* Struck through repros no longer work on HEAD.