syzbot


INFO: rcu detected stall in chrdev_open

Status: closed as invalid on 2019/12/04 14:04
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1039d, last: 1038d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in chrdev_open (2) 1 874d 874d 0/1 auto-closed as invalid on 2020/09/12 23:19
linux-4.14 INFO: rcu detected stall in chrdev_open C error 4 184d 290d 0/1 upstream: reported C repro on 2021/12/21 07:54
linux-4.19 INFO: rcu detected stall in chrdev_open (3) C error 17 9d17h 563d 0/1 upstream: reported C repro on 2021/03/22 19:09
linux-4.19 INFO: rcu detected stall in chrdev_open 1 1008d 1008d 0/1 auto-closed as invalid on 2020/05/02 02:53
upstream INFO: rcu detected stall in chrdev_open (2) C done inconclusive 55 262d 1029d 0/24 closed as invalid on 2022/02/08 10:45

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=5b2/1/0x4000000000000002 softirq=11308/11314 fqs=39 
	(t=10500 jiffies g=7029 q=125)
rcu: rcu_preempt kthread starved for 10416 jiffies! g7029 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    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: 8244 Comm: syz-executor.0 Not tainted 5.4.0-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:1514 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638
 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:mod_memcg_page_state+0x123/0x190 include/linux/memcontrol.h:653
Code: e8 f2 9e 69 00 48 83 3d 12 22 c2 07 00 74 70 e8 e3 27 2e 00 4c 89 ff 57 9d 0f 1f 44 00 00 e8 f4 c2 33 00 eb 43 e8 cd 27 2e 00 <eb> 3c e8 86 c0 33 00 48 c7 c0 28 96 0a 89 48 c1 e8 03 42 80 3c 20
RSP: 0018:ffffc900025b74f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc90001e99000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc900025b7518 R08: 000000000003a768 R09: ffffed101489becf
R10: ffffed101489becf R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a44df668
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 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
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:klist_next+0x59/0x340 lib/klist.c:377
Code: 3c 18 00 74 08 4c 89 ef e8 c4 1c cb f9 4d 8b 7d 00 49 8d 5f 50 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 9d 1c cb f9 4c 8b 23 4d 8d 75 08 4c 89 f0 48 c1
RSP: 0018:ffffc900025b7778 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02
RAX: 1ffff110153fe030 RBX: ffff8880a9ff0180 RCX: dffffc0000000000
RDX: ffffc90001e99000 RSI: 000000000000633b RDI: 000000000000633c
RBP: ffffc900025b77d8 R08: ffffffff8469041f R09: fffffbfff13c8d2d
R10: fffffbfff13c8d2d R11: 0000000000000000 R12: ffffc900025b7808
R13: ffffc900025b77f8 R14: ffff8880a3637000 R15: ffff8880a9ff0130
 class_dev_iter_next drivers/base/class.c:310 [inline]
 class_find_device+0x14e/0x270 drivers/base/class.c:414
 class_find_device_by_devt include/linux/device.h:702 [inline]
 tty_get_device drivers/tty/tty_io.c:2964 [inline]
 alloc_tty_struct+0x5e6/0x730 drivers/tty/tty_io.c:3011
 pty_common_install+0x189/0x690 drivers/tty/pty.c:399
 pty_unix98_install+0x1f/0x30 drivers/tty/pty.c:740
 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline]
 tty_init_dev+0xd0/0x500 drivers/tty/tty_io.c:1341
 ptmx_open+0xda/0x2d0 drivers/tty/pty.c:845
 chrdev_open+0x509/0x590 fs/char_dev.c:414
 do_dentry_open+0x740/0x10c0 fs/open.c:797
 vfs_open+0x73/0x80 fs/open.c:914
 do_last fs/namei.c:3412 [inline]
 path_openat+0x1397/0x44a0 fs/namei.c:3529
 do_filp_open+0x192/0x3d0 fs/namei.c:3559
 do_sys_open+0x29f/0x560 fs/open.c:1097
 __do_sys_openat fs/open.c:1124 [inline]
 __se_sys_openat fs/open.c:1118 [inline]
 __x64_sys_openat+0xa2/0xb0 fs/open.c:1118
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f30478cbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a679
RDX: 0008000000000006 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f30478cc6d4
R13: 00000000004c7edc R14: 00000000004df0e0 R15: 00000000ffffffff

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2019/12/04 00:27 upstream 76bb8b05960c ae13a849 .config log report
ci-upstream-kasan-gce-smack-root 2019/12/03 18:41 upstream 76bb8b05960c ae13a849 .config log report
ci-upstream-kasan-gce-smack-root 2019/12/03 07:25 upstream 596cf45cbf6e ab342da3 .config log report
ci-upstream-kasan-gce-smack-root 2019/12/03 00:32 upstream 596cf45cbf6e ab342da3 .config log report
* Struck through repros no longer work on HEAD.