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INFO: rcu detected stall in ipv6_rcv

Status: auto-closed as invalid on 2020/08/24 07:16
Reported-by: syzbot+f2281427b0dff76345e6@syzkaller.appspotmail.com
First crash: 2069d, last: 2069d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in ipv6_rcv (4) net 1 C done done 12 221d 722d 0/29 auto-obsoleted due to no activity on 2025/08/26 02:53
upstream INFO: rcu detected stall in ipv6_rcv net 1 7 2524d 2561d 11/29 fixed on 2019/03/06 07:43
linux-4.19 INFO: rcu detected stall in ipv6_rcv 1 1 1858d 1858d 0/1 auto-closed as invalid on 2021/03/22 19:41
upstream INFO: rcu detected stall in ipv6_rcv (3) net 1 1 940d 940d 0/29 auto-obsoleted due to no activity on 2023/08/28 06:25
linux-4.19 BUG: soft lockup in ipv6_rcv 1 C error 25 1244d 1721d 0/1 upstream: reported C repro on 2021/04/08 17:19
upstream INFO: rcu detected stall in ipv6_rcv (2) 1 C done 550 1339d 2344d 0/29 auto-obsoleted due to no activity on 2023/04/19 23:54

Sample crash report:
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
INFO: rcu_preempt self-detected stall on CPU
	1-...: (10499 ticks this GP) idle=48e/140000000000002/0 softirq=292416/292416 fqs=9 
	 (t=10500 jiffies g=85560 c=85559 q=117)
rcu_preempt kthread starved for 10478 jiffies! g85560 c85559 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
rcu_preempt     I29328     8      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 6346 Comm: syz-fuzzer Not tainted 4.14.177-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:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x50 kernel/kcov.c:93
RSP: 0018:ffff8880aeb06e28 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: ffff88809829c500 RBX: 000000000000007f RCX: 0000000000001bc8
RDX: 0000000000000100 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff88809529b122 R08: 0000000000005fd7 R09: ffffffff8a08f6f8
R10: ffff88809829cea0 R11: ffff88809829c500 R12: ffff888052a149c0
R13: 0000000000000003 R14: ffff88809529b108 R15: dffffc0000000000
 sfq_dequeue+0x125/0xdb0 net/sched/sch_sfq.c:497
 dequeue_skb net/sched/sch_generic.c:148 [inline]
 qdisc_restart net/sched/sch_generic.c:241 [inline]
 __qdisc_run+0x2b7/0xde0 net/sched/sch_generic.c:257
 __dev_xmit_skb net/core/dev.c:3223 [inline]
 __dev_queue_xmit+0x1b9b/0x25c0 net/core/dev.c:3493
 neigh_hh_output include/net/neighbour.h:490 [inline]
 neigh_output include/net/neighbour.h:498 [inline]
 ip6_finish_output2+0x1085/0x2150 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x4d9/0xaf0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip6_output+0x1c9/0x650 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:462 [inline]
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_xmit+0xd4c/0x1ea0 net/ipv6/ip6_output.c:275
 inet6_csk_xmit+0x286/0x4d0 net/ipv6/inet6_connection_sock.c:139
 __tcp_transmit_skb+0x1654/0x2dd0 net/ipv4/tcp_output.c:1131
 tcp_transmit_skb net/ipv4/tcp_output.c:1147 [inline]
 tcp_write_xmit+0x56a/0x4a60 net/ipv4/tcp_output.c:2391
 __tcp_push_pending_frames+0x9c/0x240 net/ipv4/tcp_output.c:2572
 tcp_push_pending_frames include/net/tcp.h:1778 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5123 [inline]
 tcp_rcv_established+0x612/0x15d0 net/ipv4/tcp_input.c:5570
 tcp_v6_do_rcv+0x414/0x1190 net/ipv6/tcp_ipv6.c:1301
 tcp_v6_rcv+0x24a9/0x2f80 net/ipv6/tcp_ipv6.c:1519
 ip6_input_finish+0x30e/0x15a0 net/ipv6/ip6_input.c:294
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_input+0xb9/0x310 net/ipv6/ip6_input.c:337
 dst_input include/net/dst.h:468 [inline]
 ip6_rcv_finish+0x23b/0x790 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ipv6_rcv+0xe5c/0x1c30 net/ipv6/ip6_input.c:218
 __netif_receive_skb_core+0x1e50/0x2c00 net/core/dev.c:4478
 __netif_receive_skb+0x27/0x1a0 net/core/dev.c:4516
 process_backlog+0x214/0x750 net/core/dev.c:5198
 napi_poll net/core/dev.c:5599 [inline]
 net_rx_action+0x456/0xe90 net/core/dev.c:5665
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:200
RSP: 0018:ffff88808693fdc0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd3 RBX: ffff88809829c500 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff88809829cd84
RBP: ffff8880aeb2b540 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aeb2b540
R13: ffff888044ad82c0 R14: 0000000000000000 R15: ffff8880aeb2be90
 finish_lock_switch kernel/sched/sched.h:1352 [inline]
 finish_task_switch+0x178/0x620 kernel/sched/core.c:2675
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x7c0/0x1ca0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 exit_to_usermode_loop+0x123/0x220 arch/x86/entry/common.c:153
 prepare_exit_to_usermode+0x1af/0x210 arch/x86/entry/common.c:199
 retint_user+0x8/0x18
RIP: 0033:0x41d56c
RSP: 002b:000000c42041fe90 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff10
RAX: 000000c42002b270 RBX: 000000c41fd253ff RCX: 000000000144d080
RDX: 000000c445e80000 RSI: 000000c425b58000 RDI: 0000000000000010
RBP: 000000c42041ff28 R08: 0000000000000002 R09: 0000000000000004
R10: 0000000000000020 R11: 000000c425b58320 R12: 0000000000000000
R13: ffffffffffffffff R14: 000000c424ceeab0 R15: 000000000000000e
INFO: rcu_sched self-detected stall on CPU
INFO: rcu_sched detected stalls on CPUs/tasks:
	1-...: (1 GPs behind) idle=48e/140000000000002/0 softirq=292410/292416 fqs=7 
	1-...: (1 GPs behind) idle=48e/140000000000002/0 softirq=292410/292416 fqs=7 
	
	
 (t=10565 jiffies g=48574 c=48573 q=1)
(detected by 0, t=10565 jiffies, g=48574, c=48573, q=1)
rcu_sched kthread starved for 10547 jiffies! g48574 c48573 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
Sending NMI from CPU 0 to CPUs 1:
rcu_sched       I
NMI backtrace for cpu 1
CPU: 1 PID: 6346 Comm: syz-fuzzer Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809829c500 task.stack: ffff888086938000
RIP: 0010:__memcpy+0x0/0x20 arch/x86/lib/memcpy_64.S:31
RSP: 0018:ffff8880aeb06688 EFLAGS: 00000046
RAX: fffffbfff14a94c5 RBX: dffffc0000000000 RCX: ffffffff863d3d53
RDX: 0000000000000001 RSI: ffffffff86aaf960 RDI: ffffffff8a54a620
RBP: ffffffff86aaf960 R08: ffffffff86aaf924 R09: fffffbfff14a94c5
R10: fffffbfff14a94c4 R11: ffffffff8a54a620 R12: ffffffff8a54a620
R13: ffffffff86aaf961 R14: ffff8880aeb06770 R15: 0000000000000001
FS:  000000c420349890(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcc776e00 CR3: 000000008aed3000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 memcpy include/linux/string.h:347 [inline]
 vsnprintf+0x823/0x1350 lib/vsprintf.c:2143
 sprintf+0xa7/0xd0 lib/vsprintf.c:2383
 print_time kernel/printk/printk.c:1230 [inline]
 print_prefix+0x32e/0x3a0 kernel/printk/printk.c:1253
 msg_print_text+0xae/0x1a0 kernel/printk/printk.c:1280
 console_unlock+0x300/0xec0 kernel/printk/printk.c:2374
 vprintk_emit kernel/printk/printk.c:1923 [inline]
 vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888
 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401
 printk+0x9e/0xbc kernel/printk/printk.c:1996
 sched_show_task kernel/sched/core.c:5151 [inline]
 sched_show_task.cold+0xbd/0x347 kernel/sched/core.c:5143
 rcu_check_gp_kthread_starvation+0x28d/0x2d4 kernel/rcu/tree.c:1374
 print_cpu_stall kernel/rcu/tree.c:1540 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x488/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x50 kernel/kcov.c:93
RSP: 0018:ffff8880aeb06e28 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: ffff88809829c500 RBX: 000000000000007f RCX: 0000000000001bc8
RDX: 0000000000000100 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff88809529b122 R08: 0000000000005fd7 R09: ffffffff8a08f6f8
R10: ffff88809829cea0 R11: ffff88809829c500 R12: ffff888052a149c0
R13: 0000000000000003 R14: ffff88809529b108 R15: dffffc0000000000
 sfq_dequeue+0x125/0xdb0 net/sched/sch_sfq.c:497
 dequeue_skb net/sched/sch_generic.c:148 [inline]
 qdisc_restart net/sched/sch_generic.c:241 [inline]
 __qdisc_run+0x2b7/0xde0 net/sched/sch_generic.c:257
 __dev_xmit_skb net/core/dev.c:3223 [inline]
 __dev_queue_xmit+0x1b9b/0x25c0 net/core/dev.c:3493
 neigh_hh_output include/net/neighbour.h:490 [inline]
 neigh_output include/net/neighbour.h:498 [inline]
 ip6_finish_output2+0x1085/0x2150 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x4d9/0xaf0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip6_output+0x1c9/0x650 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:462 [inline]
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_xmit+0xd4c/0x1ea0 net/ipv6/ip6_output.c:275
 inet6_csk_xmit+0x286/0x4d0 net/ipv6/inet6_connection_sock.c:139
 __tcp_transmit_skb+0x1654/0x2dd0 net/ipv4/tcp_output.c:1131
 tcp_transmit_skb net/ipv4/tcp_output.c:1147 [inline]
 tcp_write_xmit+0x56a/0x4a60 net/ipv4/tcp_output.c:2391
 __tcp_push_pending_frames+0x9c/0x240 net/ipv4/tcp_output.c:2572
 tcp_push_pending_frames include/net/tcp.h:1778 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5123 [inline]
 tcp_rcv_established+0x612/0x15d0 net/ipv4/tcp_input.c:5570
 tcp_v6_do_rcv+0x414/0x1190 net/ipv6/tcp_ipv6.c:1301
 tcp_v6_rcv+0x24a9/0x2f80 net/ipv6/tcp_ipv6.c:1519
 ip6_input_finish+0x30e/0x15a0 net/ipv6/ip6_input.c:294
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_input+0xb9/0x310 net/ipv6/ip6_input.c:337
 dst_input include/net/dst.h:468 [inline]
 ip6_rcv_finish+0x23b/0x790 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ipv6_rcv+0xe5c/0x1c30 net/ipv6/ip6_input.c:218
 __netif_receive_skb_core+0x1e50/0x2c00 net/core/dev.c:4478
 __netif_receive_skb+0x27/0x1a0 net/core/dev.c:4516
 process_backlog+0x214/0x750 net/core/dev.c:5198
 napi_poll net/core/dev.c:5599 [inline]
 net_rx_action+0x456/0xe90 net/core/dev.c:5665
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:200
RSP: 0018:ffff88808693fdc0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd3 RBX: ffff88809829c500 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff88809829cd84
RBP: ffff8880aeb2b540 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aeb2b540
R13: ffff888044ad82c0 R14: 0000000000000000 R15: ffff8880aeb2be90
 finish_lock_switch kernel/sched/sched.h:1352 [inline]
 finish_task_switch+0x178/0x620 kernel/sched/core.c:2675
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x7c0/0x1ca0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 exit_to_usermode_loop+0x123/0x220 arch/x86/entry/common.c:153
 prepare_exit_to_usermode+0x1af/0x210 arch/x86/entry/common.c:199
 retint_user+0x8/0x18
RIP: 0033:0x41d56c
RSP: 002b:000000c42041fe90 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff10
RAX: 000000c42002b270 RBX: 000000c41fd253ff RCX: 000000000144d080
RDX: 000000c445e80000 RSI: 000000c425b58000 RDI: 0000000000000010
RBP: 000000c42041ff28 R08: 0000000000000002 R09: 0000000000000004
R10: 0000000000000020 R11: 000000c425b58320 R12: 0000000000000000
R13: ffffffffffffffff R14: 000000c424ceeab0 R15: 000000000000000e
Code: eb ca e8 74 d3 45 fb e9 50 ff ff ff e8 9a d3 45 fb e9 70 ff ff ff e8 90 d3 45 fb eb 88 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <eb> 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 
rcu_sched kthread starved for 10547 jiffies! g48574 c48573 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
29920     9      2 0x80000000
rcu_sched       I
Call Trace:
29920     9      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 6346 Comm: syz-fuzzer Not tainted 4.14.177-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:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x50 kernel/kcov.c:93
RSP: 0018:ffff8880aeb06e28 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: ffff88809829c500 RBX: 000000000000007f RCX: 0000000000001bc8
RDX: 0000000000000100 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff88809529b122 R08: 0000000000005fd7 R09: ffffffff8a08f6f8
R10: ffff88809829cea0 R11: ffff88809829c500 R12: ffff888052a149c0
R13: 0000000000000003 R14: ffff88809529b108 R15: dffffc0000000000
 sfq_dequeue+0x125/0xdb0 net/sched/sch_sfq.c:497
 dequeue_skb net/sched/sch_generic.c:148 [inline]
 qdisc_restart net/sched/sch_generic.c:241 [inline]
 __qdisc_run+0x2b7/0xde0 net/sched/sch_generic.c:257
 __dev_xmit_skb net/core/dev.c:3223 [inline]
 __dev_queue_xmit+0x1b9b/0x25c0 net/core/dev.c:3493
 neigh_hh_output include/net/neighbour.h:490 [inline]
 neigh_output include/net/neighbour.h:498 [inline]
 ip6_finish_output2+0x1085/0x2150 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x4d9/0xaf0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip6_output+0x1c9/0x650 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:462 [inline]
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_xmit+0xd4c/0x1ea0 net/ipv6/ip6_output.c:275
 inet6_csk_xmit+0x286/0x4d0 net/ipv6/inet6_connection_sock.c:139
 __tcp_transmit_skb+0x1654/0x2dd0 net/ipv4/tcp_output.c:1131
 tcp_transmit_skb net/ipv4/tcp_output.c:1147 [inline]
 tcp_write_xmit+0x56a/0x4a60 net/ipv4/tcp_output.c:2391
 __tcp_push_pending_frames+0x9c/0x240 net/ipv4/tcp_output.c:2572
 tcp_push_pending_frames include/net/tcp.h:1778 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5123 [inline]
 tcp_rcv_established+0x612/0x15d0 net/ipv4/tcp_input.c:5570
 tcp_v6_do_rcv+0x414/0x1190 net/ipv6/tcp_ipv6.c:1301
 tcp_v6_rcv+0x24a9/0x2f80 net/ipv6/tcp_ipv6.c:1519
 ip6_input_finish+0x30e/0x15a0 net/ipv6/ip6_input.c:294
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ip6_input+0xb9/0x310 net/ipv6/ip6_input.c:337
 dst_input include/net/dst.h:468 [inline]
 ip6_rcv_finish+0x23b/0x790 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:250 [inline]
 NF_HOOK include/linux/netfilter.h:244 [inline]
 ipv6_rcv+0xe5c/0x1c30 net/ipv6/ip6_input.c:218
 __netif_receive_skb_core+0x1e50/0x2c00 net/core/dev.c:4478
 __netif_receive_skb+0x27/0x1a0 net/core/dev.c:4516
 process_backlog+0x214/0x750 net/core/dev.c:5198
 napi_poll net/core/dev.c:5599 [inline]
 net_rx_action+0x456/0xe90 net/core/dev.c:5665
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:200
RSP: 0018:ffff88808693fdc0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd3 RBX: ffff88809829c500 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff88809829cd84
RBP: ffff8880aeb2b540 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aeb2b540
R13: ffff888044ad82c0 R14: 0000000000000000 R15: ffff8880aeb2be90
 finish_lock_switch kernel/sched/sched.h:1352 [inline]
 finish_task_switch+0x178/0x620 kernel/sched/core.c:2675
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x7c0/0x1ca0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 exit_to_usermode_loop+0x123/0x220 arch/x86/entry/common.c:153
 prepare_exit_to_usermode+0x1af/0x210 arch/x86/entry/common.c:199
 retint_user+0x8/0x18
RIP: 0033:0x41d56c
RSP: 002b:000000c42041fe90 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff10
RAX: 000000c42002b270 RBX: 000000c41fd253ff RCX: 000000000144d080
RDX: 000000c445e80000 RSI: 000000c425b58000 RDI: 0000000000000010
RBP: 000000c42041ff28 R08: 0000000000000002 R09: 0000000000000004
R10: 0000000000000020 R11: 000000c425b58320 R12: 0000000000000000
R13: ffffffffffffffff R14: 000000c424ceeab0 R15: 000000000000000e

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/04/26 07:16 linux-4.14.y 050272a0423e b8bb8e5f .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.