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INFO: rcu detected stall in proc_reg_read (4)

Status: closed as invalid on 2020/01/09 08:13
Subsystems: kernel
[Documentation on labels]
First crash: 2003d, last: 2002d
▶ ▼ Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in proc_reg_read mm 6 2386d 2465d 0/29 closed as dup on 2019/01/02 16:24
upstream INFO: rcu detected stall in proc_reg_read (2) kernel 36 2037d 2039d 0/29 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in proc_reg_read (5) fs 1 1777d 1777d 0/29 auto-closed as invalid on 2020/11/18 23:09
upstream INFO: rcu detected stall in proc_reg_read (6) fs 1 1520d 1520d 0/29 auto-closed as invalid on 2021/08/03 06:54
linux-4.19 INFO: rcu detected stall in proc_reg_read syz error 11 901d 1627d 0/1 upstream: reported syz repro on 2021/01/17 20:31
upstream INFO: rcu detected stall in proc_reg_read (3) kernel 3 2003d 2003d 0/29 closed as invalid on 2020/01/08 05:23

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=c46/1/0x4000000000000002 softirq=12280/12280 fqs=9 
	(t=10501 jiffies g=6701 q=235)
rcu: rcu_preempt kthread starved for 10484 jiffies! g6701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28984    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8200 Comm: rsyslogd Not tainted 5.5.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:186
Code: 84 00 00 00 00 00 55 48 89 e5 53 48 89 fb e8 13 00 00 00 48 8b 3d f4 f4 ed 07 48 89 de e8 84 f4 3b 00 5b 5d c3 cc 48 8b 04 24 <65> 48 8b 0c 25 c0 1d 02 00 65 8b 15 38 5f 8b 7e f7 c2 00 01 1f 00
RSP: 0018:ffffc90001d4fa50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81489244 RBX: ffffea00027430c0 RCX: ffff8880981a6080
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00027430c0
RBP: ffffc90001d4fa90 R08: dffffc0000000000 R09: fffffbfff124248a
R10: fffffbfff124248a R11: 0000000000000000 R12: ffff88809c21e620
R13: dffffc0000000000 R14: 1ffff11013843cc4 R15: ffff8880984e55f8
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 do_syslog+0xdb0/0x1770 kernel/printk/printk.c:1525
 kmsg_read+0x94/0xd0 fs/proc/kmsg.c:40
 proc_reg_read+0x1e2/0x2d0 fs/proc/inode.c:223
 __vfs_read+0xb8/0x730 fs/read_write.c:425
 vfs_read+0x1dd/0x420 fs/read_write.c:461
 ksys_read+0x117/0x220 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:595
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f88588c11fd
Code: d1 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 5e fa ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 a7 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f8855e60e30 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000001add650 RCX: 00007f88588c11fd
RDX: 0000000000000fff RSI: 00007f88576955a0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000001ac8260 R09: 0000000004000001
R10: 0000000000000001 R11: 0000000000000293 R12: 000000000065e420
R13: 00007f8855e619c0 R14: 00007f8858f06040 R15: 0000000000000003

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/08 12:47 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 12:22 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 11:26 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 11:14 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 09:19 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 09:08 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 08:22 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 07:07 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/08 06:59 upstream ae6088216ce4 6738e0b3 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.