syzbot


INFO: rcu detected stall in bad_area
Status: closed as invalid on 2022/02/08 10:45
Reported-by: syzbot+79fe77a41f0f085ece70@syzkaller.appspotmail.com
First crash: 888d, last: 356d

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

Fix bisection: the fix commit could be any of (bisect log):
  2187f215ebaa Merge tag 'for-5.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
  303392fd5c16 Merge tag 'leds-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds
Patch testing requests:
Created Duration User Patch Repo Result
2020/10/11 13:28 12m rkovhaev@gmail.com upstream report log
2020/09/17 08:24 11m rkovhaev@gmail.com upstream report log
2020/09/08 15:00 12m rkovhaev@gmail.com upstream report log

Sample crash report:
hrtimer: interrupt took 59918 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=9705, q=83)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295004244-4294993742), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor069 R  running task    28568 10245  10207 0x80000004
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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x90/0xe0 kernel/locking/spinlock.c:191
Code: 48 c7 c0 d8 34 93 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 3f f1 ca 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 e1 77 88 f9 65 8b 05 d2 da 39 78
RSP: 0000:ffffc90001fe7ca8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132669b RBX: 0000000000000286 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: 0000000000000286
RBP: ffffc90001fe7cb8 R08: ffff8880914ba100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888083a2ac00
R13: ffff8880914ba820 R14: 000000000000000a R15: 000000000000000b
 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
 force_sig_info_to_task+0x2a2/0x340 kernel/signal.c:1329
 force_sig_fault_to_task kernel/signal.c:1671 [inline]
 force_sig_fault+0xbe/0x100 kernel/signal.c:1678
 __bad_area_nosemaphore+0x32e/0x420 arch/x86/mm/fault.c:904
 __bad_area arch/x86/mm/fault.c:933 [inline]
 bad_area+0x69/0x80 arch/x86/mm/fault.c:939
 do_user_addr_fault arch/x86/mm/fault.c:1404 [inline]
 __do_page_fault+0x9eb/0xd80 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x590 arch/x86/mm/fault.c:1530
 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x401515
Code: 00 00 00 be b4 fe 4a 00 e8 38 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:00007f35767f7b20 EFLAGS: 00010206
RAX: 0000000002ed3b50 RBX: 00000000006dcc28 RCX: 0000000000406cd7
RDX: 1482b7b55b3372eb RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000006dcc20 R08: 00007f35767f7b20 R09: 00000000006dcc20
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000006dcc2c
R13: 00007ffc626d62cf R14: 00007f35767f89c0 R15: 00000000006dcc20
rcu: rcu_preempt kthread starved for 10502 jiffies! g9705 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 (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2019/12/19 06:02 upstream 2187f215ebaa 79b211f7 .config log report syz C
ci-upstream-kasan-gce-selinux-root 2020/03/01 00:45 upstream f8788d86ab28 59b57593 .config log report
ci-upstream-kasan-gce-selinux-root 2019/12/26 11:00 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-kasan-gce-root 2019/12/25 15:44 upstream 46cf053efec6 be5c2c81 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/02/27 18:36 linux-next bdc5461b23ca 59b57593 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/02/13 03:50 linux-next 129759899765 84f4fc8a .config log report