syzbot


INFO: rcu detected stall in do_signal (4)

Status: closed as invalid on 2022/02/08 10:44
Reported-by: syzbot+7e600afa7f6059f9a30e@syzkaller.appspotmail.com
First crash: 971d, last: 738d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: INFO: rcu detected stall in do_signal (log)
Repro: C syz .config

Fix bisection: failed (bisect log)
similar bugs (9):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in do_signal (4) 3 216d 258d 0/1 auto-closed as invalid on 2022/05/09 06:50
upstream INFO: rcu detected stall in do_signal (3) 2 984d 984d 0/23 closed as invalid on 2019/12/04 14:04
linux-4.19 INFO: rcu detected stall in do_signal (2) 1 944d 944d 0/1 auto-closed as invalid on 2020/05/11 22:29
upstream INFO: rcu detected stall in do_signal 2 1383d 1402d 0/23 auto-closed as invalid on 2019/04/28 15:41
linux-4.14 INFO: rcu detected stall in do_signal (2) 1 527d 527d 0/1 auto-closed as invalid on 2021/07/02 05:05
linux-4.19 INFO: rcu detected stall in do_signal 1 1205d 1205d 0/1 auto-closed as invalid on 2019/10/23 10:40
linux-4.14 INFO: rcu detected stall in do_signal 7 655d 969d 0/1 auto-closed as invalid on 2021/02/24 19:41
linux-4.19 INFO: rcu detected stall in do_signal (3) 6 492d 793d 0/1 auto-closed as invalid on 2021/08/06 21:07
upstream INFO: rcu detected stall in do_signal (2) 3 988d 988d 0/23 closed as invalid on 2019/11/29 14:24

Sample crash report:
hrtimer: interrupt took 92494 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=8669, q=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295016466-4295005964), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor765 R  running task    28552  9407   9389 0x00000000
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5954 [inline]
 sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5929
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:538 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq.cold+0xaf4/0xc02 kernel/rcu/tree.c:2271
 update_process_times+0x2d/0x70 kernel/time/timer.c:1726
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x4f/0x80 kernel/locking/spinlock.c:199
Code: c0 e8 34 93 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 52 f5 ca 01 00 74 20 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 e7 7b 88 f9 65 8b 05 d8 de 39 78 85 c0 74 06 41
RSP: 0000:ffffc90001f47ca0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669d RBX: 0000000000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff888095ca8b54
RBP: ffffc90001f47ca8 R08: ffff888095ca82c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a8ef0b80
R13: ffff8880a8ef0cc0 R14: dffffc0000000000 R15: 000000000000000b
 spin_unlock_irq include/linux/spinlock.h:388 [inline]
 get_signal+0x1bee/0x24f0 kernel/signal.c:2737
 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160
 prepare_exit_to_usermode+0x321/0x3a0 arch/x86/entry/common.c:195
 ret_from_intr+0x26/0x36
RIP: 0033:0x401505
Code: 00 00 00 be b4 fe 4a 00 e8 48 ee ff ff 48 85 c0 0f 85 d2 fe ff ff e9 4a ff ff ff e8 55 d9 04 00 48 6b 44 24 28 18 8b 7c 24 38 <48> 8b 88 50 00 00 20 48 8b 90 48 00 00 20 48 8b b0 40 00 00 20 e8
RSP: 002b:00007f51c6df1b20 EFLAGS: 00010202
RAX: 0000000002f54358 RBX: 00000000006dcc28 RCX: 0000000000406cc7
RDX: 60b237aef639e3c2 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000006dcc20 R08: 00007f51c6df1b20 R09: 00000000006dcc20
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000006dcc2c
R13: 00007ffcd25bbb6f R14: 00007f51c6df29c0 R15: 00000000006dcc20
rcu: rcu_preempt kthread starved for 10502 jiffies! g8669 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29272    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4081
 schedule+0xdc/0x2b0 kernel/sched/core.c:4155
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Crashes (30):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2019/12/19 09:30 upstream 2187f215ebaa 79b211f7 .config log report syz C
ci-upstream-linux-next-kasan-gce-root 2019/12/27 13:29 linux-next 7ddd09fc4b74 be5c2c81 .config log report syz C
ci-upstream-kasan-gce-smack-root 2020/08/05 16:58 upstream 442489c21923 b7129355 .config log report
ci-upstream-kasan-gce-selinux-root 2020/08/04 13:09 upstream bcf876870b95 196277c4 .config log report
ci-upstream-kasan-gce 2020/07/19 16:48 upstream f932d58abc38 9c812472 .config log report
ci-upstream-kasan-gce 2020/07/17 05:46 upstream f8456690ba8e 54b3c45e .config log report
ci-upstream-kasan-gce-selinux-root 2020/07/16 22:55 upstream f8456690ba8e 54b3c45e .config log report
ci-upstream-kasan-gce 2020/07/06 02:49 upstream 7cc2a8ea1048 51095195 .config log report
ci-upstream-kasan-gce-smack-root 2020/06/30 08:21 upstream 4e99b32169e8 a2cdad9d .config log report
ci-upstream-kasan-gce-root 2020/06/29 19:40 upstream 4e99b32169e8 a2cdad9d .config log report
ci-upstream-kasan-gce-smack-root 2020/06/24 07:58 upstream 7ae77150d94d 54566aff .config log report
ci-upstream-kasan-gce-selinux-root 2020/06/16 20:41 upstream 7ae77150d94d 559fbe2d .config log report
ci-upstream-kasan-gce-root 2020/06/02 22:37 upstream f359287765c0 52fd7b7d .config log report
ci-upstream-kasan-gce-smack-root 2020/05/11 10:51 upstream 2ef96a5bb12b f8f57555 .config log report
ci-upstream-kasan-gce-selinux-root 2020/03/07 08:55 upstream fb279f4e2386 fd2a5f28 .config log report
ci-upstream-kasan-gce-root 2020/02/04 00:34 upstream 754beeec1d90 93e5e335 .config log report
ci-upstream-kasan-gce-root 2020/01/14 17:28 upstream b3a987b0264d 32881205 .config log report
ci-upstream-kasan-gce-root 2020/01/14 11:29 upstream b3a987b0264d 32881205 .config log report
ci-upstream-kasan-gce-smack-root 2020/01/08 10:54 upstream ae6088216ce4 6738e0b3 .config log report
ci-upstream-kasan-gce-root 2019/12/27 18:54 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-kasan-gce-root 2019/12/27 07:16 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-kasan-gce-root 2019/12/26 23:09 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-kasan-gce-root 2019/12/26 04:58 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-kasan-gce-root 2019/12/16 04:08 upstream 07c4b9e9f71a eef6e580 .config log report
ci-upstream-kasan-gce-386 2020/07/02 19:22 upstream cd77006e01b3 bed10395 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/07/20 04:17 linux-next 4c43049f19a2 9c812472 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/03/07 08:44 linux-next 770fbb32d34e fd2a5f28 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/02/03 14:24 linux-next 2747d5fdab78 93e5e335 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/01/07 17:52 linux-next 264673852033 1bcd407e .config log report
ci-upstream-linux-next-kasan-gce-root 2019/12/25 23:04 linux-next 7ddd09fc4b74 be5c2c81 .config log report