BUG: soft lockup in tcp_write_timer

Status: auto-closed as invalid on 2019/10/25 14:11
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+97ff1b2561a76fa6c8f1@syzkaller.appspotmail.com
First crash: 2569d, last: 2561d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
BUG: soft lockup in tcp_write_timer 0 (1) 2019/07/26 10:55
▶ ▼ Similar bugs (18)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in tcp_write_timer (10) perf mm net 1 3 148d 178d 0/29 closed as invalid on 2026/03/27 01:43
linux-4.19 BUG: soft lockup in tcp_write_timer (3) 1 2 1316d 1329d 0/1 upstream: reported on 2022/12/17 21:41
linux-4.14 BUG: soft lockup in tcp_write_timer 1 2 2282d 2361d 0/1 auto-closed as invalid on 2020/09/05 12:42
linux-4.19 BUG: soft lockup in tcp_write_timer (2) 1 2 1725d 1789d 0/1 auto-closed as invalid on 2022/03/16 10:56
linux-5.15 INFO: rcu detected stall in tcp_write_timer 1 4 662d 715d 0/3 auto-obsoleted due to no activity on 2025/01/22 08:13
android-54 BUG: soft lockup in tcp_write_timer 1 1 461d 461d 0/2 auto-obsoleted due to no activity on 2025/08/01 21:51
linux-4.19 BUG: soft lockup in tcp_write_timer 1 1 1954d 1954d 0/1 auto-closed as invalid on 2021/07/30 14:52
upstream BUG: soft lockup in tcp_write_timer (9) net 1 2 242d 246d 0/29 closed as invalid on 2026/01/07 12:42
upstream BUG: soft lockup in tcp_write_timer (4) mm 1 4 762d 787d 26/29 fixed on 2024/07/09 19:14
upstream BUG: soft lockup in tcp_write_timer (2) kvm 1 1 1565d 1565d 0/29 auto-closed as invalid on 2022/06/24 22:31
linux-5.15 INFO: rcu detected stall in tcp_write_timer (4) origin:lts-only 1 syz error 4 78d 159d 0/3 upstream: reported syz repro on 2026/03/01 05:59
upstream BUG: soft lockup in tcp_write_timer (3) net 1 6 942d 1049d 0/29 closed as invalid on 2024/03/18 17:07
linux-6.6 INFO: rcu detected stall in tcp_write_timer 1 5 20d 150d 0/2 upstream: reported on 2026/03/10 11:19
upstream BUG: soft lockup in tcp_write_timer (7) net 1 1 328d 328d 0/29 closed as invalid on 2025/09/29 07:16
upstream BUG: soft lockup in tcp_write_timer (8) mm 1 1 303d 303d 0/29 closed as invalid on 2025/11/04 11:28
upstream BUG: soft lockup in tcp_write_timer (6) bpf 1 1 375d 375d 0/29 closed as invalid on 2025/09/01 08:24
upstream BUG: soft lockup in tcp_write_timer (5) mm net 1 8 431d 493d 0/29 closed as invalid on 2025/07/11 15:27
android-5-15 BUG: soft lockup in tcp_write_timer 1 11 725d 838d 0/2 auto-obsoleted due to no activity on 2024/11/10 05:27

Sample crash report:
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [swapper/0:0]
Modules linked in:
irq event stamp: 96975
hardirqs last  enabled at (96975): [<ffffffff873f91fc>] default_idle+0x1c/0x360 arch/x86/kernel/process.c:580
hardirqs last disabled at (96974): [<ffffffff81503165>] do_idle+0x145/0x770 kernel/sched/idle.c:250
softirqs last  enabled at (96942): [<ffffffff876006cd>] __do_softirq+0x6cd/0x98c kernel/softirq.c:319
softirqs last disabled at (96931): [<ffffffff8144ff7b>] invoke_softirq kernel/softirq.c:373 [inline]
softirqs last disabled at (96931): [<ffffffff8144ff7b>] irq_exit+0x19b/0x1e0 kernel/softirq.c:413
CPU: 0 PID: 0 Comm: swapper/0 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:cpu_relax arch/x86/include/asm/processor.h:656 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:84 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0x132/0x9f0 kernel/locking/qspinlock.c:325
Code: 00 00 00 48 8b 45 d0 65 48 33 04 25 28 00 00 00 0f 85 37 07 00 00 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f3 90 <e9> 73 ff ff ff 8b 45 98 4c 8d 65 d8 3d 00 01 00 00 0f 84 e5 00 00
RSP: 0018:ffff8880ae809b48 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff88805e7dee88 RCX: ffffffff8158f457
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88805e7dee88
RBP: ffff8880ae809c08 R08: 1ffff1100bcfbdd1 R09: ffffed100bcfbdd2
R10: ffffed100bcfbdd1 R11: ffff88805e7dee8b R12: 0000000000000001
R13: 0000000000000003 R14: ffffed100bcfbdd1 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffbc1ed1000 CR3: 0000000065e51000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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 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:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: f8 7d 6d fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d d4 9a 48 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d c4 9a 48 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 1e 41 20 fa e8 29
RSP: 0018:ffffffff88c07c50 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e97 RBX: 0000000000000000 RCX: 1ffffffff134c076
RDX: dffffc0000000000 RSI: ffffffff8177a69e RDI: ffffffff873f91fc
RBP: ffffffff88c07c80 R08: ffffffff88c7a1c0 R09: fffffbfff118f439
R10: fffffbfff118f438 R11: ffffffff88c7a1c7 R12: 0000000000000001
R13: ffffffff89609600 R14: 0000000000000000 R15: 0000000000000001
 default_enter_idle+0x71/0xf0 drivers/cpuidle/cpuidle-haltpoll.c:27
 cpuidle_enter_state+0xee/0xf70 drivers/cpuidle/cpuidle.c:229
 cpuidle_enter+0x4f/0xa0 drivers/cpuidle/cpuidle.c:344
 call_cpuidle kernel/sched/idle.c:117 [inline]
 cpuidle_idle_call kernel/sched/idle.c:201 [inline]
 do_idle+0x4bb/0x770 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 rest_init+0x245/0x37b init/main.c:451
 arch_call_rest_init+0xe/0x1b
 start_kernel+0x912/0x951 init/main.c:785
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:472
 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:453
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4129 Comm: syz-executor.5 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:cpu_relax arch/x86/include/asm/processor.h:656 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:84 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0x132/0x9f0 kernel/locking/qspinlock.c:325
Code: 00 00 00 48 8b 45 d0 65 48 33 04 25 28 00 00 00 0f 85 37 07 00 00 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f3 90 <e9> 73 ff ff ff 8b 45 98 4c 8d 65 d8 3d 00 01 00 00 0f 84 e5 00 00
RSP: 0018:ffff8880ae909210 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88805e7dee88 RCX: ffffffff8158f457
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88805e7dee88
RBP: ffff8880ae9092d0 R08: 1ffff1100bcfbdd1 R09: ffffed100bcfbdd2
R10: ffffed100bcfbdd1 R11: ffff88805e7dee8b R12: 0000000000000001
R13: 0000000000000003 R14: ffffed100bcfbdd1 R15: 0000000000000001
FS:  000055555743d940(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31928000 CR3: 0000000091a3d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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:00007ffede594770 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000413511
RDX: 0000000000000000 RSI: 0000000000000dcf RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000bd644dcf R09: 00000000bd644dd3
R10: 00007ffede594850 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 00000000007613a8 R15: ffffffffffffffff

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/08/03 06:24 linux-next 7b4980e0bcf4 6affd8e8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/03 04:45 linux-next 7b4980e0bcf4 6affd8e8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/31 18:46 linux-next ce96e791d6a7 c692b5bd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/31 11:09 linux-next ce96e791d6a7 7c7ded69 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/30 12:09 linux-next 70f4b4ac1655 f28bf2a5 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/28 18:10 linux-next fde50b96be82 c85e1c5b .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/28 08:53 linux-next fde50b96be82 c85e1c5b .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/28 03:45 linux-next fde50b96be82 c85e1c5b .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/27 07:05 linux-next fde50b96be82 c85e1c5b .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/26 10:57 linux-next fde50b96be82 3e5d1beb .config console log report ci-upstream-linux-next-kasan-gce-root
2019/07/26 03:07 linux-next 13bf6d6a51df 732bc5a0 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.