INFO: rcu detected stall in tcp_write_timer

Status: upstream: reported on 2026/03/10 11:19
Reported-by: syzbot+e2f484aebb1ce6cef6be@syzkaller.appspotmail.com
First crash: 155d, last: 25d
▶ ▼ Similar bugs (28)
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 2017d 2073d 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 759d 759d 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 668d 720d 0/3 auto-obsoleted due to no activity on 2025/01/22 08:13
upstream INFO: rcu detected stall in tcp_write_timer net 1 3 2567d 2561d 0/29 auto-closed as invalid on 2019/10/25 14:11
linux-5.15 INFO: rcu detected stall in tcp_write_timer (2) 1 2 453d 537d 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 1884d 1884d 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 553d 783d 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 768d 792d 26/29 fixed on 2024/07/09 19:14
linux-6.1 INFO: rcu detected stall in tcp_write_timer (2) 1 3 40d 160d 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 83d 165d 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 302d 318d 0/3 auto-obsoleted due to no activity on 2026/01/22 20:12
linux-4.14 INFO: rcu detected stall in tcp_write_timer 1 4 2169d 2411d 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 2298d 2352d 0/1 auto-closed as invalid on 2020/08/26 06:46
upstream BUG: soft lockup in tcp_write_timer (10) perf mm net 1 3 153d 183d 0/29 closed as invalid on 2026/03/27 01:43
linux-4.19 BUG: soft lockup in tcp_write_timer (3) 1 2 1321d 1334d 0/1 upstream: reported on 2022/12/17 21:41
linux-4.19 BUG: soft lockup in tcp_write_timer (2) 1 2 1730d 1794d 0/1 auto-closed as invalid on 2022/03/16 10:56
android-54 BUG: soft lockup in tcp_write_timer 1 1 466d 466d 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 1959d 1959d 0/1 auto-closed as invalid on 2021/07/30 14:52
upstream BUG: soft lockup in tcp_write_timer (9) net 1 2 248d 252d 0/29 closed as invalid on 2026/01/07 12:42
upstream BUG: soft lockup in tcp_write_timer (2) kvm 1 1 1570d 1570d 0/29 auto-closed as invalid on 2022/06/24 22:31
upstream BUG: soft lockup in tcp_write_timer (3) net 1 6 947d 1055d 0/29 closed as invalid on 2024/03/18 17:07
upstream BUG: soft lockup in tcp_write_timer (7) net 1 1 333d 333d 0/29 closed as invalid on 2025/09/29 07:16
upstream BUG: soft lockup in tcp_write_timer (8) mm 1 1 309d 309d 0/29 closed as invalid on 2025/11/04 11:28
upstream BUG: soft lockup in tcp_write_timer (6) bpf 1 1 381d 381d 0/29 closed as invalid on 2025/09/01 08:24
upstream BUG: soft lockup in tcp_write_timer (5) mm net 1 8 436d 498d 0/29 closed as invalid on 2025/07/11 15:27
android-5-15 BUG: soft lockup in tcp_write_timer 1 11 731d 843d 0/2 auto-obsoleted due to no activity on 2024/11/10 05:27
linux-4.14 BUG: soft lockup in tcp_write_timer 1 2 2287d 2367d 0/1 auto-closed as invalid on 2020/09/05 12:42
upstream BUG: soft lockup in tcp_write_timer net 1 11 2567d 2574d 0/29 auto-closed as invalid on 2019/10/25 14:11

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=fb6c/1/0x4000000000000000 softirq=62399/62399 fqs=86
rcu: 	(t=10500 jiffies g=84353 q=523 ncpus=2)
rcu: rcu_preempt kthread starved for 10123 jiffies! g84353 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:26920 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </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: 17441 Comm: syz.2.4490 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:perf_prepare_sample+0xbac/0x1db0 kernel/events/core.c:7837
Code: 4c 24 20 80 3c 01 00 74 09 48 8d 7b 10 e8 bc 67 31 00 4c 01 6b 10 49 bd 00 00 00 00 00 fc ff df 48 8b 44 24 28 42 80 3c 28 00 <4c> 8b 64 24 18 74 08 48 89 df e8 95 67 31 00 80 4b 01 20 4c 89 fe
RSP: 0018:ffffc90000006cc0 EFLAGS: 00000046
RAX: 1ffff92000000df8 RBX: ffffc90000006fc0 RCX: 1ffff92000000dfa
RDX: ffff88804c55da00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000006db0 R08: ffff88804c55da07 R09: 1ffff110098abb40
R10: dffffc0000000000 R11: ffffed10098abb41 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc90000007058 R15: 000000000002b040
FS:  00007f533c22e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f533c1a9ff8 CR3: 0000000044e0f000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __perf_event_output kernel/events/core.c:7966 [inline]
 perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7987
 __perf_event_overflow+0x461/0x660 kernel/events/core.c:9712
 perf_event_overflow kernel/events/core.c:9733 [inline]
 perf_swevent_hrtimer+0x437/0x610 kernel/events/core.c:11222
 __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
 __hrtimer_run_queues+0x4e8/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215
Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d ec 87 05 0d 48 89 de 5b e9 23 a7 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d c0 d2 7c 7e 65 8b 15 c1 d2 7c 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900000074f0 EFLAGS: 00000246
RAX: ffffffff813b24f8 RBX: 1ffff92000000eb9 RCX: ffffffff972ee403
RDX: ffff88804c55da00 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90000007618 R08: ffffc90000007690 R09: 0000000000000028
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc9000505fca8
R13: ffffc900000075c8 R14: 0000000000000000 R15: dffffc0000000000
 unwind_next_frame+0x128/0x2990 arch/x86/kernel/unwind_orc.c:482
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 skb_kfree_head net/core/skbuff.c:946 [inline]
 skb_free_head net/core/skbuff.c:958 [inline]
 skb_release_data+0x609/0x7f0 net/core/skbuff.c:988
 skb_release_all net/core/skbuff.c:1054 [inline]
 __kfree_skb+0x57/0x70 net/core/skbuff.c:1068
 tcp_write_queue_purge+0x140/0x310 net/ipv4/tcp.c:3007
 tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4446
 tcp_write_err net/ipv4/tcp_timer.c:72 [inline]
 tcp_probe_timer net/ipv4/tcp_timer.c:407 [inline]
 tcp_write_timer_handler+0x666/0x910 net/ipv4/tcp_timer.c:696
 tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg+0x39/0x230 arch/x86/kernel/unwind_orc.c:403
Code: 89 54 24 10 48 89 34 24 49 89 ff 48 bd 00 00 00 00 00 fc ff df e8 27 95 4b 00 49 8d 7f 08 48 89 f8 48 c1 e8 03 48 89 44 24 08 <80> 3c 28 00 74 05 e8 ec 0c a4 00 4d 8b 77 08 49 8d 7f 10 49 89 fd
RSP: 0018:ffffc9000505eda8 EFLAGS: 00000a02
RAX: 1ffff92000a0bdda RBX: ffffffff8f137e0d RCX: ffff88804c55da00
RDX: 0000000000000003 RSI: ffffc9000505eff0 RDI: ffffc9000505eed0
RBP: dffffc0000000000 R08: ffff88804c55da00 R09: 0000000000000003
R10: 0000000000000004 R11: ffffc900198bd000 R12: ffffc9000505ef60
R13: ffffc9000505eec8 R14: ffffffff8f137e0c R15: ffffc9000505eec8
 unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2721 [inline]
 call_rcu+0x153/0x900 kernel/rcu/tree.c:2837
 context_switch kernel/sched/core.c:5384 [inline]
 __schedule+0x15b6/0x4660 kernel/sched/core.c:6700
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 unwind_next_frame+0x201c/0x2990 arch/x86/kernel/unwind_orc.c:672
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 memcg_free_slab_cgroups mm/slab.h:463 [inline]
 unaccount_slab mm/slab.h:651 [inline]
 __free_slab+0xbe/0x2a0 mm/slub.c:2097
 __slab_free+0x35a/0x400 mm/slub.c:3736
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc_lru+0x175/0x2b0 mm/slub.c:3526
 alloc_inode_sb include/linux/fs.h:2959 [inline]
 sock_alloc_inode+0x28/0xc0 net/socket.c:308
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049
 sock_alloc net/socket.c:634 [inline]
 __sock_create+0x12d/0x940 net/socket.c:1535
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0xd7/0x1b0 net/socket.c:1715
 __do_sys_socket net/socket.c:1729 [inline]
 __se_sys_socket net/socket.c:1727 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1727
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f533b39de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f533c22e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f533b625fa0 RCX: 00007f533b39de99
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000022
RBP: 00007f533b433eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f533b626038 R14: 00007f533b625fa0 R15: 00007fff2d6287a8
 </TASK>
CPU: 1 PID: 17438 Comm: syz.3.4489 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline]
RIP: 0010:__local_bh_enable_ip+0x142/0x1c0 kernel/softirq.c:413
Code: 8a e8 32 92 39 09 65 66 8b 05 2a 6c b1 7e 66 85 c0 75 54 bf 01 00 00 00 e8 2b 1d 0a 00 e8 d6 06 3b 00 fb 65 8b 05 f6 6b b1 7e <85> c0 75 05 e8 a5 50 ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc900001f05c0 EFLAGS: 00000282
RAX: 0000000000000101 RBX: 0000000000000200 RCX: 6ed348307bf18000
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc900001f0650 R08: ffffffff911e75ff R09: 1ffffffff223cebf
R10: dffffc0000000000 R11: fffffbfff223cec0 R12: ffffffff8958591b
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200003e0b8
FS:  00007f090f9c36c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000007754c000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 ip6t_do_table+0x13c4/0x1570 net/ipv6/netfilter/ip6_tables.c:375
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0x1331/0x1480 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4029
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:smp_call_function_many_cond+0xc51/0x1190 kernel/smp.c:763
Code: 00 74 0c 48 c7 c7 60 0d f9 8c e8 ba 66 63 00 48 8b 7c 24 68 ff 15 bf 16 7d 0b 80 7c 24 50 00 0f 85 f2 f7 ff ff e8 bf ee 0a 00 <83> 7c 24 5c 00 0f 84 af 01 00 00 8b 44 24 7c 39 84 24 80 00 00 00
RSP: 0018:ffffc9000b20f760 EFLAGS: 00000283
RAX: ffffffff817bf64d RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc90014a71000 RSI: 0000000000002c57 RDI: 0000000000002c58
RBP: ffffc9000b20f8e0 R08: ffffffff911e7507 R09: 1ffffffff223cea0
R10: dffffc0000000000 R11: fffffbfff223cea1 R12: ffff8880b8f3d3c0
R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff81306fb0
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
 text_poke_bp_batch+0x31e/0x980 arch/x86/kernel/alternative.c:2432
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
 static_key_enable+0x1a/0x20 kernel/jump_label.c:220
 tracepoint_add_func+0x985/0xa10 kernel/tracepoint.c:363
 tracepoint_probe_register_prio kernel/tracepoint.c:513 [inline]
 tracepoint_probe_register+0x5e/0x90 kernel/tracepoint.c:533
 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline]
 perf_trace_event_init+0x4d4/0x9b0 kernel/trace/trace_event_perf.c:202
 perf_trace_init+0x238/0x2d0 kernel/trace/trace_event_perf.c:226
 perf_tp_event_init+0x8d/0x110 kernel/events/core.c:10228
 perf_try_init_event+0x12b/0x3c0 kernel/events/core.c:11852
 perf_init_event kernel/events/core.c:11922 [inline]
 perf_event_alloc+0xed4/0x2150 kernel/events/core.c:12203
 __do_sys_perf_event_open kernel/events/core.c:12710 [inline]
 __se_sys_perf_event_open+0x740/0x1c60 kernel/events/core.c:12601
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f090eb9de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f090f9c3028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f090ee26090 RCX: 00007f090eb9de99
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000040
RBP: 00007f090ec33eaf R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f090ee26128 R14: 00007f090ee26090 R15: 00007fffd5b2ec28
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/18 10:21 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in tcp_write_timer
2026/05/29 04:32 linux-6.6.y 0a40c6fbd105 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in tcp_write_timer
2026/05/22 23:04 linux-6.6.y eac8889a3a1c 5f091fcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in tcp_write_timer
2026/03/10 11:19 linux-6.6.y 4fc00fe35d46 6972f302 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in tcp_write_timer
2026/06/17 19:14 linux-6.6.y 924b4a879cbb b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: soft lockup in tcp_write_timer
* Struck through repros no longer work on HEAD.