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hrtimer: interrupt took 39149 ns rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=cefc/1/0x4000000000000000 softirq=12505/12507 fqs=12 rcu: (t=10502 jiffies g=9325 q=1023 ncpus=2) rcu: rcu_preempt kthread starved for 10479 jiffies! g9325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27720 pid:17 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 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+0x313/0x1590 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5965 Comm: syz.3.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:379 [inline] RIP: 0010:__rcu_read_lock+0x0/0x60 kernel/rcu/tree_plugin.h:402 Code: b3 6d 00 e9 db fb ff ff 44 89 f1 80 e1 07 38 c1 0f 8c 62 fb ff ff 4c 89 f7 e8 7c b4 6d 00 e9 55 fb ff ff 0f 1f 80 00 00 00 00 <f3> 0f 1e fa 53 65 48 8b 1d a3 fe 91 7e 48 81 c3 3c 04 00 00 48 89 RSP: 0018:ffffc900001efc78 EFLAGS: 00000006 RAX: ffffffff81ae5ac0 RBX: ffff8880318f8000 RCX: ffff888078f43c00 RDX: 0000000000010100 RSI: ffffc900001efe80 RDI: ffff8880318f8000 RBP: ffffc900001efd88 R08: ffff8880318f848b R09: 1ffff1100631f091 R10: dffffc0000000000 R11: ffffed100631f092 R12: dffffc0000000000 R13: ffff8880318f8000 R14: ffffc900001f0338 R15: 1ffff9200003df94 FS: 0000555582a1b500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000001c768 CR3: 000000002f9ea000 CR4: 00000000003506e0 Call Trace: <IRQ> rcu_read_lock include/linux/rcupdate.h:784 [inline] __perf_event_output kernel/events/core.c:7972 [inline] perf_event_output_forward+0xb2/0x3e0 kernel/events/core.c:7995 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_event_overflow kernel/events/core.c:9741 [inline] perf_swevent_hrtimer+0x439/0x610 kernel/events/core.c:11230 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e1/0xc40 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x3c9/0x9c0 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:seqcount_lockdep_reader_access+0x19a/0x1d0 include/linux/seqlock.h:105 Code: 00 4d 85 e4 75 16 e8 85 c8 0f 00 eb 15 e8 7e c8 0f 00 e8 09 b8 10 09 4d 85 e4 74 ea e8 6f c8 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900001f03e0 EFLAGS: 00000246 RAX: ffffffff81776381 RBX: 0000000000000000 RCX: ffff888078f43c00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900001f0498 R08: ffffffff911cc5ff R09: 1ffffffff22398bf R10: dffffc0000000000 R11: fffffbfff22398c0 R12: 0000000000000200 R13: 000001fb6ca015d2 R14: 1ffff9200003e07c R15: dffffc0000000000 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_with_offset+0x103/0x330 kernel/time/timekeeping.c:891 ktime_get_real include/linux/timekeeping.h:79 [inline] netif_rx_internal+0x344/0x4e0 net/core/dev.c:5153 __netif_rx+0x78/0xc0 net/core/dev.c:5196 veth_forward_skb drivers/net/veth.c:325 [inline] veth_xmit+0x550/0x9f0 drivers/net/veth.c:378 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660 __dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454 dev_queue_xmit include/linux/netdevice.h:3113 [inline] hsr_xmit net/hsr/hsr_forward.c:382 [inline] hsr_forward_do net/hsr/hsr_forward.c:473 [inline] hsr_forward_skb+0x1335/0x2140 net/hsr/hsr_forward.c:626 send_hsr_supervision_frame+0x5fb/0xb90 net/hsr/hsr_device.c:346 hsr_announce+0x198/0x350 net/hsr/hsr_device.c:402 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x30/0x80 kernel/kcov.c:320 Code: 04 24 65 48 8b 0d 80 85 7c 7e 65 8b 15 81 85 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e <8b> 91 f8 15 00 00 83 fa 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc RSP: 0018:ffffc9000376fc90 EFLAGS: 00000246 RAX: ffffffff813ca4e1 RBX: 00000000295da500 RCX: ffff888078f43c00 RDX: 0000000000000000 RSI: 00000000295da500 RDI: 00003fffffffffff RBP: ffffc9000376fda8 R08: ffff8880295da55f R09: 1ffff110052bb4ab R10: dffffc0000000000 R11: ffffed10052bb4ac R12: 0000000000000000 R13: ffff888078f43c00 R14: 000000000000002e R15: 0000000000000000 pfn_valid include/linux/mmzone.h:2008 [inline] __virt_addr_valid+0xe1/0x540 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0xd/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:477 task_work_add+0xd9/0x470 kernel/task_work.c:82 fput+0xdd/0x1a0 fs/file_table.c:440 filp_close+0x10f/0x150 fs/open.c:1547 __range_close fs/file.c:698 [inline] __close_range+0x368/0x660 fs/file.c:755 __do_sys_close_range fs/open.c:1599 [inline] __se_sys_close_range fs/open.c:1596 [inline] __x64_sys_close_range+0x7a/0x90 fs/open.c:1596 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: 0033:0x7f102e59ce59 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:00007ffc422167b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ffc422168a0 RCX: 00007f102e59ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000001c768 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2d020000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f102e815fac R14: 00007f102e815fa8 R15: 00007f102e815fa0 </TASK> CPU: 0 PID: 5961 Comm: syz.2.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 12 c6 35 09 65 66 8b 05 4a 4a b1 7e 66 85 c0 75 54 bf 01 00 00 00 e8 8b 22 0a 00 e8 b6 32 3b 00 fb 65 8b 05 16 4a b1 7e <85> c0 75 05 e8 95 31 ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000007880 EFLAGS: 00000282 RAX: 0000000000000302 RBX: 0000000000000201 RCX: 18c28050e2fc8300 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9a20 RBP: ffffc90000007900 R08: ffffffff911cc5ff R09: 1ffffffff22398bf R10: dffffc0000000000 R11: fffffbfff22398c0 R12: ffffffff8a640b93 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000000f10 FS: 0000555587d6c500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2db63fff CR3: 000000007ac0c000 CR4: 00000000003506f0 Call Trace: <IRQ> spin_unlock_bh include/linux/spinlock.h:396 [inline] hsr_register_frame_out+0x263/0x3a0 net/hsr/hsr_framereg.c:-1 hsr_forward_do net/hsr/hsr_forward.c:443 [inline] hsr_forward_skb+0xdfb/0x2140 net/hsr/hsr_forward.c:626 send_hsr_supervision_frame+0x5fb/0xb90 net/hsr/hsr_device.c:346 hsr_announce+0x198/0x350 net/hsr/hsr_device.c:402 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> ab c8 ca f6 65 8b 05 3c f0 71 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000378fca0 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 18c28050e2fc8300 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc9000378fd30 R08: ffffffff911cc60f R09: 1ffffffff22398c1 R10: dffffc0000000000 R11: fffffbfff22398c2 R12: dffffc0000000000 R13: 1ffff920006f1fb8 R14: ffff8880258f6c00 R15: 1ffff920006f1f94 __do_sys_perf_event_open kernel/events/core.c:12958 [inline] __se_sys_perf_event_open+0x183e/0x1c50 kernel/events/core.c:12609 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: 0033:0x7f1f46d9ce59 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:00007fff243e66c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f1f47015fa0 RCX: 00007f1f46d9ce59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f1f46e32d6f R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1f47015fac R14: 00007f1f47015fa0 R15: 00007f1f47015fa0 </TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026/05/30 23:57 | linux-6.6.y | 0a40c6fbd105 | 6b4a8443 | .config | console log | report | syz / log | C | [disk image] [vmlinux] [kernel image] | ci2-linux-6-6-kasan-perf | INFO: rcu detected stall in hsr_announce | |
| 2026/05/28 20:14 | linux-6.6.y | 0a40c6fbd105 | 681715f7 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-6-6-kasan-perf | BUG: soft lockup in hsr_announce |