syzbot


INFO: rcu detected stall in mptcp_worker

Status: auto-closed as invalid on 2022/04/22 04:04
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 315d, last: 315d

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=ae1/1/0x4000000000000000 softirq=61956/61962 fqs=0 
	(t=12208 jiffies g=88925 q=149)
rcu: rcu_preempt kthread starved for 12208 jiffies! g88925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:R  running task     stack:28736 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xa9a/0x4900 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 950 Comm: kworker/u4:4 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x70 kernel/kcov.c:286
Code: 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 <89> f1 65 48 8b 34 25 40 70 02 00 e8 14 f9 ff ff 84 c0 74 4b 48 8b
RSP: 0018:ffffc90004a9f9f0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880b9d3fca0 RCX: 0000000000000000
RDX: ffff88801b3c8000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff816bfc86 R11: 0000000000000000 R12: ffffed10173a7f95
R13: 0000000000000001 R14: ffff8880b9d3fca8 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e424000 CR3: 000000000b88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_many_cond+0x476/0xc20 kernel/smp.c:969
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1112 [inline]
 text_poke_bp_batch+0x355/0x560 arch/x86/kernel/alternative.c:1350
 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1448 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x1da/0x400 kernel/jump_label.c:830
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:734 [inline]
 toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:726
 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298
 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4593 Comm: kworker/1:12 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events mptcp_worker
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 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:3878 [inline]
 rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2597
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
Code: 74 24 10 e8 4a 03 11 f8 48 89 ef e8 02 79 11 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 43 43 04 f8 65 8b 05 cc e8 b6 76 85 c0 74 0a 5b 5d c3 e8 90 2f
RSP: 0018:ffffc90004a7fb08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff2002656
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff88807a759bd0 R08: 0000000000000001 R09: ffffffff8ffa2b2f
R10: 0000000000000001 R11: 000000000008808a R12: ffff88807a759bd0
R13: ffff88807a759c18 R14: ffff88807a759c18 R15: ffff88807a759c18
 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
 ref_tracker_dir_exit.cold+0x137/0x1e3 lib/ref_tracker.c:37
 __put_net+0x15/0x70 net/core/net_namespace.c:640
 put_net include/net/net_namespace.h:268 [inline]
 put_net_track include/net/net_namespace.h:342 [inline]
 __sk_destruct+0x6d2/0x920 net/core/sock.c:2042
 sk_destruct+0xbd/0xe0 net/core/sock.c:2058
 __sk_free+0xef/0x3d0 net/core/sock.c:2069
 sk_free+0x78/0xa0 net/core/sock.c:2080
 sock_put include/net/sock.h:1912 [inline]
 mptcp_worker+0x779/0xbb0 net/mptcp/protocol.c:2513
 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298
 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 48 89             	add    %cl,-0x77(%rax)
   5:	7c 30                	jl     0x37
   7:	e8 48 89 4c 30       	callq  0x304c8954
   c:	f0 4c 89 54 d8 20    	lock mov %r10,0x20(%rax,%rbx,8)
  12:	48 89 10             	mov    %rdx,(%rax)
  15:	5b                   	pop    %rbx
  16:	c3                   	retq
  17:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  1e:	41 89 f8             	mov    %edi,%r8d
  21:	bf 03 00 00 00       	mov    $0x3,%edi
  26:	4c 8b 14 24          	mov    (%rsp),%r10
* 2a:	89 f1                	mov    %esi,%ecx <-- trapping instruction
  2c:	65 48 8b 34 25 40 70 	mov    %gs:0x27040,%rsi
  33:	02 00
  35:	e8 14 f9 ff ff       	callq  0xfffff94e
  3a:	84 c0                	test   %al,%al
  3c:	74 4b                	je     0x89
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-net-kasan-gce 2022/01/22 04:01 net-next fe8152b38d3a 214351e1 .config log report info INFO: rcu detected stall in mptcp_worker
* Struck through repros no longer work on HEAD.