INFO: rcu detected stall in advance_sched (2)

Status: upstream: reported on 2026/09/27 09:01
Subsystems: net
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+e0fa723f5960605c7ddb@syzkaller.appspotmail.com
First crash: 161d, last: 1d16h
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ID Workflow Result Correct Bug Created Started Finished Revision
b79371b3 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in advance_sched (2) 2026/05/26 01:44 2026/05/26 01:44 2026/05/26 02:41 c69befb3
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[syzbot] [net?] INFO: rcu detected stall in advance_sched (2) 0 (1) 2026/09/27 09:01
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in advance_sched net 1 14 254d 332d 0/29 auto-obsoleted due to no activity on 2026/04/09 04:02

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P29
rcu: 	(detected by 1, t=10592 jiffies, g=56017, q=13328 ncpus=2)
task:ktimers/1       state:R  running task     stack:24168 pid:29    tgid:29    ppid:2      task_flags:0x4208040 flags:0x00080010
Call Trace:
 <IRQ>
 sched_show_task+0x4aa/0x5f0 kernel/sched/core.c:8250
 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
 print_other_cpu_stall+0xfbf/0x1350 kernel/rcu/tree_stall.h:683
 check_cpu_stall kernel/rcu/tree_stall.h:860 [inline]
 rcu_pending kernel/rcu/tree.c:3744 [inline]
 rcu_sched_clock_irq+0x9fe/0x10e0 kernel/rcu/tree.c:2749
 update_process_times+0x234/0x2d0 kernel/time/timer.c:2475
 tick_sched_handle kernel/time/tick-sched.c:296 [inline]
 tick_nohz_handler+0x38f/0x6b0 kernel/time/tick-sched.c:317
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x3a0/0xaf0 kernel/time/hrtimer.c:2131
 hrtimer_interrupt+0x4c2/0xa80 kernel/time/hrtimer.c:2250
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:6021
Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 c4 bd 4d 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4b d1 03 00 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc90000a3fab8 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8dae029b RDI: ffffffff8bcc4a80
RBP: 00000000ffffffff R08: 0000000000000100 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1f64530 R12: 0000000000000246
R13: ffff88801d2c3e80 R14: ffff888060f6e400 R15: 0000000000000004
 lock_is_held include/linux/lockdep.h:249 [inline]
 advance_sched+0xea/0xc90 net/sched/sch_taprio.c:933
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2131
 hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2148
 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 run_ktimerd+0x6a/0x100 kernel/softirq.c:1174
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10596 jiffies! g56017 f0x0 RCU_GP_WAIT_FQS(5) ->state=I
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=32843
rcu: rcu_preempt kthread starved for 10597 jiffies! g56017 f0x0 RCU_GP_WAIT_FQS(5) ->state=I ->cpu=1
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:I stack:27784 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:6021
Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 c4 bd 4d 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4b d1 03 00 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc90000a3fab8 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8dae029b RDI: ffffffff8bcc4a80
RBP: 00000000ffffffff R08: 0000000000000100 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1f64530 R12: 0000000000000246
R13: ffff88801d2c3e80 R14: ffff888060f6e400 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff888125cc4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3101f81e80 CR3: 000000000dfb0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_is_held include/linux/lockdep.h:249 [inline]
 advance_sched+0xea/0xc90 net/sched/sch_taprio.c:933
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2131
 hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2148
 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 run_ktimerd+0x6a/0x100 kernel/softirq.c:1174
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (31):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/25 22:41 upstream aa98230e410f f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/23 08:51 upstream fe2ec83746e5 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/21 15:47 upstream 93f51579e7df 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/21 07:42 upstream 93f51579e7df 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/12 08:12 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/05 05:47 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/04 01:29 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/04 01:29 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/03 06:32 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/01 18:49 upstream 786262be6048 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/01 14:48 upstream 786262be6048 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/09/01 14:48 upstream 786262be6048 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/31 19:52 upstream cee9395acd80 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/31 17:49 upstream cee9395acd80 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/29 13:47 upstream cf72cbb39da8 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/27 07:34 upstream 73e3f0710014 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/21 02:50 upstream 7f063b2f17ea 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/20 07:00 upstream 98f21c54f995 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/19 22:45 upstream 98f21c54f995 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/18 18:58 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/17 21:06 upstream 8d3ae59288f1 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/17 21:02 upstream 8d3ae59288f1 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/08/02 18:58 upstream 2d2338c93da7 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/06/20 19:33 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/06/13 13:00 upstream 062871f1371b 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/05/19 05:31 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/05/19 05:30 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/05/19 02:15 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/05/19 02:14 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/04/25 17:33 upstream 897d54018cc9 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
2026/04/18 18:35 upstream 8541d8f725c6 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in advance_sched
* Struck through repros no longer work on HEAD.