INFO: rcu detected stall in tcp_write_timer

Status: auto-closed as invalid on 2019/10/25 14:11
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+1f80b70f1e8f1df46319@syzkaller.appspotmail.com
First crash: 2552d, last: 2549d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
INFO: rcu detected stall in tcp_write_timer 0 (1) 2019/08/08 16:45
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in tcp_write_timer (2) bpf 1 2 1999d 2055d 0/29 auto-closed as invalid on 2021/05/03 11:59
upstream INFO: rcu detected stall in tcp_write_timer (4) net 1 1 741d 741d 0/29 auto-obsoleted due to no activity on 2024/10/13 08:46
linux-5.15 INFO: rcu detected stall in tcp_write_timer 1 4 650d 702d 0/3 auto-obsoleted due to no activity on 2025/01/22 08:13
linux-5.15 INFO: rcu detected stall in tcp_write_timer (2) 1 2 435d 519d 0/3 auto-obsoleted due to no activity on 2025/08/25 02:13
upstream INFO: rcu detected stall in tcp_write_timer (3) net 1 1 1866d 1866d 0/29 auto-closed as invalid on 2021/09/13 13:17
linux-6.1 INFO: rcu detected stall in tcp_write_timer 1 16 535d 765d 0/3 auto-obsoleted due to no activity on 2025/05/16 12:07
upstream BUG: soft lockup in tcp_write_timer (4) mm 1 4 750d 775d 26/29 fixed on 2024/07/09 19:14
linux-6.1 INFO: rcu detected stall in tcp_write_timer (2) 1 3 22d 142d 0/3 upstream: reported on 2026/03/06 03:16
linux-5.15 INFO: rcu detected stall in tcp_write_timer (4) origin:lts-only 1 syz error 4 65d 147d 0/3 upstream: reported syz repro on 2026/03/01 05:59
linux-5.15 INFO: rcu detected stall in tcp_write_timer (3) 1 2 284d 300d 0/3 auto-obsoleted due to no activity on 2026/01/22 20:12
linux-6.6 INFO: rcu detected stall in tcp_write_timer 1 5 8d01h 138d 0/2 upstream: reported on 2026/03/10 11:19
linux-4.14 INFO: rcu detected stall in tcp_write_timer 1 4 2151d 2393d 0/1 auto-closed as invalid on 2021/01/02 05:45
linux-4.19 INFO: rcu detected stall in tcp_write_timer 1 2 2280d 2334d 0/1 auto-closed as invalid on 2020/08/26 06:46

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=ec2/1/0x4000000000000004 softirq=59968/59968 fqs=0 
	(t=10501 jiffies g=97849 q=61)
rcu: rcu_preempt kthread starved for 10502 jiffies! g97849 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29120    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x15b0 kernel/sched/core.c:3921
 schedule+0xa8/0x270 kernel/sched/core.c:3985
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1893
 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline]
 rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 18553 Comm: syz-executor.4 Not tainted 5.3.0-rc2-next-20190802 #58
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+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf 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:2736 [inline]
 rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183
 update_process_times+0x32/0x80 kernel/time/timer.c:1724
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299
 __run_hrtimer kernel/time/hrtimer.c:1493 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1555
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1617
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1093
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
RIP: 0010:check_memory_region+0x13/0x1a0 mm/kasan/generic.c:191
Code: 48 89 e5 e8 9f b2 90 05 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 34 01 00 00 48 b8 ff ff ff ff ff 7f ff ff <55> 0f b6 d2 48 39 c7 48 89 e5 41 55 41 54 53 0f 86 07 01 00 00 4c
RSP: 0018:ffff8880ae809b30 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: ffff7fffffffffff RBX: ffff8880a40d83c8 RCX: ffffffff8158f457
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880a40d83c8
RBP: ffff8880ae809b38 R08: 1ffff1101481b079 R09: ffffed101481b07a
R10: ffffed101481b079 R11: ffff8880a40d83cb R12: 0000000000000001
R13: 0000000000000003 R14: ffffed101481b079 R15: 0000000000000001
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 virt_spin_lock arch/x86/include/asm/qspinlock.h:83 [inline]
 native_queued_spin_lock_slowpath+0xb7/0x9f0 kernel/locking/qspinlock.c:325
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:642 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:81 [inline]
 do_raw_spin_lock+0x20e/0x2e0 kernel/locking/spinlock_debug.c:113
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:338 [inline]
 tcp_write_timer+0x2b/0x1e0 net/ipv4/tcp_timer.c:610
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1771 [inline]
 __run_timers kernel/time/timer.c:1738 [inline]
 run_timer_softirq+0x6c0/0x17f0 kernel/time/timer.c:1784
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:do_syscall_64+0x5b/0x760 arch/x86/entry/common.c:284
Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 4f 06 00 00 48 83 3d 77 52 d2 07 00 0f 84 9c 04 00 00 e8 7c 81 71 00 fb 66 0f 1f 44 00 00 <65> 4c 8b 34 25 40 fe 01 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2
RSP: 0018:ffff88805c0aff20 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8880995e0200 RBX: 0000000000000003 RCX: 1ffffffff134c076
RDX: 0000000000000000 RSI: ffffffff8100a244 RDI: ffffffff8100a216
RBP: ffff88805c0aff48 R08: ffff8880995e0200 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805c0aff58
R13: ffffffff88d2f4b0 R14: 0000000000000000 R15: 0000000000000000
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413511
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fffa40dc650 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 0000000000413511
RDX: fffffffffffffff7 RSI: 0000000000000290 RDI: 0000000000000013
RBP: 0000000000000001 R08: 00000000d4010293 R09: ffffffffffffffff
R10: 00007fffa40dc730 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000760e60 R15: ffffffffffffffff
Sending NMI from CPU 0 to CPUs 1:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.247 msecs
NMI backtrace for cpu 1
CPU: 1 PID: 18548 Comm: syz-executor.3 Not tainted 5.3.0-rc2-next-20190802 #58
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:83 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0xaa/0x9f0 kernel/locking/qspinlock.c:325
Code: 0f 1f 44 00 00 49 89 fe 49 89 fd 41 bc 01 00 00 00 49 c1 ee 03 41 83 e5 07 48 b8 00 00 00 00 00 fc ff df 49 01 c6 41 83 c5 03 <be> 04 00 00 00 48 89 df e8 f9 fc 53 00 41 0f b6 06 41 38 c5 7c 08
RSP: 0018:ffff8880ae909210 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff8880a40d83c8 RCX: ffffffff8158f457
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880a40d83c8
RBP: ffff8880ae9092d0 R08: 1ffff1101481b079 R09: ffffed101481b07a
R10: ffffed101481b079 R11: ffff8880a40d83cb R12: 0000000000000001
R13: 0000000000000003 R14: ffffed101481b079 R15: 0000000000000001
FS:  000055555666b940(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e43d000 CR3: 0000000097551000 CR4: 00000000001406e0
Call Trace:
 <IRQ>
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:642 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:81 [inline]
 do_raw_spin_lock+0x20e/0x2e0 kernel/locking/spinlock_debug.c:113
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:343 [inline]
 release_sock+0x20/0x1c0 net/core/sock.c:2932
 wait_on_pending_writer+0x20f/0x420 net/tls/tls_main.c:91
 tls_sk_proto_cleanup+0x2c5/0x3e0 net/tls/tls_main.c:295
 tls_sk_proto_unhash+0x90/0x3f0 net/tls/tls_main.c:330
 tcp_set_state+0x5b9/0x7d0 net/ipv4/tcp.c:2235
 tcp_done+0xe2/0x320 net/ipv4/tcp.c:3824
 tcp_reset+0x132/0x500 net/ipv4/tcp_input.c:4123
 tcp_validate_incoming+0xa2d/0x1660 net/ipv4/tcp_input.c:5483
 tcp_rcv_established+0x6b5/0x1e70 net/ipv4/tcp_input.c:5691
 tcp_v6_do_rcv+0x41e/0x12c0 net/ipv6/tcp_ipv6.c:1371
 tcp_v6_rcv+0x31f1/0x3500 net/ipv6/tcp_ipv6.c:1603
 ip6_protocol_deliver_rcu+0x2fe/0x1660 net/ipv6/ip6_input.c:397
 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:438
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish+0x1de/0x2f0 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:4999
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5113
 process_backlog+0x206/0x750 net/core/dev.c:5924
 napi_poll net/core/dev.c:6347 [inline]
 net_rx_action+0x508/0x10c0 net/core/dev.c:6413
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1080
 </IRQ>
 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:337
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 inet_csk_listen_stop+0x1e0/0x850 net/ipv4/inet_connection_sock.c:993
 tcp_close+0xd5b/0x10e0 net/ipv4/tcp.c:2338
 inet_release+0xed/0x200 net/ipv4/af_inet.c:427
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:470
 __sock_release+0xce/0x280 net/socket.c:590
 sock_close+0x1e/0x30 net/socket.c:1268
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x65f/0x760 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413511
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffe0d8302d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000413511
RDX: 0000000000000000 RSI: ffffffff873d3e80 RDI: 0000000000000006
RBP: 0000000000000001 R08: ffffffff8128fdec R09: 000000004acb79b9
R10: 00007ffe0d8303b0 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000761bd8 R15: ffffffffffffffff

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/08/03 06:49 linux-next 7b4980e0bcf4 6affd8e8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/01 12:35 linux-next 882e8691130b c692b5bd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/31 11:11 linux-next ce96e791d6a7 7c7ded69 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.