syzbot


INFO: rcu detected stall in sched_show_task

Status: auto-obsoleted due to no activity on 2023/09/24 04:40
Reported-by: syzbot+11140f943253f655cd7a@syzkaller.appspotmail.com
First crash: 545d, last: 545d

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=b85/1/0x4000000000000000 softirq=113195/113196 fqs=0 
	(t=13383 jiffies g=172825 q=420)
rcu: rcu_preempt kthread starved for 13383 jiffies! g172825 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27000 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
 rcu_gp_fqs_loop+0x2af/0xf70 kernel/rcu/tree.c:1959
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2132
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 18165 Comm: kworker/1:4 Not tainted 5.15.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: rcu_gp wait_rcu_exp_gp
RIP: 0010:kasan_check_range+0x1b0/0x290 mm/kasan/generic.c:189
Code: 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b 41 5e 41 5f <5d> c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7 c6 00 00 ff
RSP: 0018:ffffc90000dd0b50 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000042 RCX: ffffffff816285a9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fbcb108
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1f79622
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000003
R13: ffff88803cab0ae8 R14: ffff88803cab0000 R15: ffff88803cab0b88
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f863e901000 CR3: 00000000233b5000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 __lock_acquire+0x1209/0x1ff0 kernel/locking/lockdep.c:5008
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
 seqcount_lockdep_reader_access+0xf8/0x220 include/linux/seqlock.h:103
 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
 ktime_get_update_offsets_now+0x89/0x420 kernel/time/timekeeping.c:2303
 hrtimer_update_base kernel/time/hrtimer.c:631 [inline]
 hrtimer_interrupt+0x12f/0x980 kernel/time/hrtimer.c:1793
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:console_trylock_spinning+0x36b/0x3f0 kernel/printk/printk.c:1909
Code: 0f 84 75 ff ff ff e8 24 ec 19 00 fb 31 db eb 41 e8 1a ec 19 00 e8 55 db b4 08 4d 85 ed 74 cd e8 0b ec 19 00 fb bb 01 00 00 00 <48> c7 c7 a0 8e 7f 8c 31 f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00
RSP: 0018:ffffc90007327700 EFLAGS: 00000293
RAX: ffffffff81660d45 RBX: 0000000000000001 RCX: ffff88803cab0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900073277d0 R08: ffffffff81660cfe R09: fffffbfff1f79625
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000e64ee0
R13: 0000000000000200 R14: 0000000000000046 R15: dffffc0000000000
 vprintk_emit+0xa1/0x150 kernel/printk/printk.c:2267
 _printk+0xd1/0x111 kernel/printk/printk.c:2289
 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline]
 show_trace_log_lvl+0x388/0x410 arch/x86/kernel/dumpstack.c:285
 sched_show_task+0x4a4/0x640 kernel/sched/core.c:8628
 synchronize_rcu_expedited_wait kernel/rcu/tree_exp.h:569 [inline]
 rcu_exp_wait_wake kernel/rcu/tree_exp.h:587 [inline]
 rcu_exp_sel_wait_wake+0x123c/0x1c00 kernel/rcu/tree_exp.h:621
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 28997 Comm: syz-executor.5 Not tainted 5.15.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
 rcu_pending kernel/rcu/tree.c:3888 [inline]
 rcu_sched_clock_irq+0xf26/0x1770 kernel/rcu/tree.c:2606
 update_process_times+0x196/0x200 kernel/time/timer.c:1788
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x22d/0x3c0 kernel/time/tick-sched.c:1430
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__unix_dgram_recvmsg+0x63b/0x1260 net/unix/af_unix.c:2349
Code: 41 80 3c 1f 00 74 0a e8 13 c6 d6 f8 48 8b 7c 24 20 48 83 3f 00 0f 84 b1 00 00 00 4d 8d 75 18 4c 89 f0 48 c1 e8 03 80 3c 18 00 <74> 08 4c 89 f7 e8 eb c5 d6 f8 41 bc 18 05 00 00 4d 03 26 4c 89 e0
RSP: 0018:ffffc900036df740 EFLAGS: 00000246
RAX: 1ffff1100466c453 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8a8afc60 RDI: ffffc900036dfd40
RBP: ffffc900036df8f0 R08: dffffc0000000000 R09: fffffbfff1f79636
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff888023362280 R14: ffff888023362298 R15: 1ffff920006dbfa8
 ____sys_recvmsg+0x286/0x530
 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2673
 do_recvmmsg+0x36f/0x8f0 net/socket.c:2767
 __sys_recvmmsg net/socket.c:2846 [inline]
 __do_sys_recvmmsg net/socket.c:2869 [inline]
 __se_sys_recvmmsg net/socket.c:2862 [inline]
 __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2862
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fa1e7ca0389
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa1e61f1168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fa1e7dc0050 RCX: 00007fa1e7ca0389
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 00007fa1e7ceb493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6a822a7f R14: 00007fa1e61f1300 R15: 0000000000022000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/16 04:39 linux-5.15.y 471e639e59d1 f3921d4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sched_show_task
* Struck through repros no longer work on HEAD.