syzbot |
sign-in | mailing list | source | docs |
rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=9b8c/1/0x4000000000000000 softirq=14912/14912 fqs=1 rcu: (t=10501 jiffies g=13085 q=403 ncpus=2) rcu: rcu_preempt kthread starved for 10500 jiffies! g13085 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:26728 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: 6284 Comm: syz.1.119 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:206 [inline] RIP: 0010:unwind_next_frame+0x1cd/0x2970 arch/x86/kernel/unwind_orc.c:494 Code: e9 65 04 00 00 49 89 df 48 89 6c 24 10 48 c7 c3 00 00 00 81 4c 89 ff 48 c7 c6 00 00 00 81 e8 1a f4 4b 00 49 81 ff 00 00 00 81 <40> 0f 92 c5 4c 89 ff 48 c7 c6 00 00 c0 8a e8 00 f4 4b 00 49 81 ff RSP: 0018:ffffc900001f0148 EFLAGS: 00000006 RAX: ffffffff813b3986 RBX: ffffffff81000000 RCX: ffff88807d9f5a00 RDX: 0000000000000100 RSI: ffffffff81000000 RDI: ffffffff81aeec33 RBP: ffffc900001f0330 R08: ffff88807d9f5a00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001f02e0 R13: dffffc0000000000 R14: ffffc900001f0315 R15: ffffffff81aeec33 FS: 00007faa94df76c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000001 CR3: 000000002b8e8000 CR4: 00000000003506e0 DR0: 0000200000000180 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: <IRQ> __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] perf_callchain_kernel+0x2a2/0x690 arch/x86/events/core.c:-1 get_perf_callchain+0x231/0x510 kernel/events/callchain.c:204 perf_callchain kernel/events/core.c:7742 [inline] perf_sample_save_callchain include/linux/perf_event.h:1232 [inline] perf_prepare_sample+0x3c7/0x1df0 kernel/events/core.c:7786 __perf_event_output kernel/events/core.c:7974 [inline] perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7995 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_swevent_overflow kernel/events/core.c:9803 [inline] perf_swevent_event+0x319/0x570 kernel/events/core.c:9854 perf_tp_event+0x5f9/0x1520 kernel/events/core.c:10381 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10300 perf_trace_preemptirq_template+0x269/0x330 include/trace/events/preemptirq.h:14 trace_irq_enable+0xbb/0xe0 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0a ac d6 f6 48 89 df e8 c2 80 d7 f6 e8 bd 98 fb f6 fb bf 01 00 00 00 <e8> a2 87 ca f6 65 8b 05 33 b0 71 75 85 c0 74 02 5b c3 e8 30 97 6e RSP: 0018:ffffc900001f0cb0 EFLAGS: 00000282 RAX: 35101300a36fa900 RBX: ffff8880b8f295c0 RCX: 35101300a36fa900 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc900001f0e10 R08: ffffffff911cd5ff R09: 1ffffffff2239abf R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: ffff8880b8f295c0 R13: 1ffff110171e52c0 R14: ffff888031a68318 R15: ffffc900001f0d60 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x533/0x800 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:generic_exec_single+0x481/0x4f0 kernel/smp.c:418 Code: 75 11 e8 c2 06 0b 00 48 85 db 75 16 e8 b8 06 0b 00 eb 15 e8 b1 06 0b 00 e8 9c 36 0c 09 48 85 db 74 ea e8 a2 06 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08 RSP: 0018:ffffc900191efa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88807d9f5a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900191efad0 R08: ffffffff911cd5ff R09: 1ffffffff2239abf R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: 1ffff9200323df44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff9200323df65 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959 __do_sys_perf_event_open kernel/events/core.c:12957 [inline] __se_sys_perf_event_open+0x1836/0x1c50 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: 0033:0x7faa93f9ce59 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:00007faa94df7028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007faa94216090 RCX: 00007faa93f9ce59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000003c0 RBP: 00007faa94032d6f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007faa94216128 R14: 00007faa94216090 R15: 00007ffe9c5b8b78 </TASK> CPU: 0 PID: 6283 Comm: syz.1.119 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_cmp4+0x2e/0x90 kernel/kcov.c:287 Code: 48 8b 04 24 65 48 8b 15 20 89 7c 7e 65 8b 0d 21 89 7c 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 <74> 52 8b 8a f8 15 00 00 83 f9 03 75 47 48 8b 8a 00 16 00 00 44 8b RSP: 0018:ffffc90000007548 EFLAGS: 00000246 RAX: ffffffff813b39d7 RBX: ffffffff81000000 RCX: 0000000000000100 RDX: ffff88807d9f3c00 RSI: 0000000000003b69 RDI: 000000000009c000 RBP: 000000000009c000 R08: ffffc90000007600 R09: 0000000000000000 R10: ffffc90000007688 R11: fffff52000000edd R12: ffffc90000007688 R13: dffffc0000000000 R14: ffffc900000076bd R15: 0000000000003b69 FS: 00007faa94e186c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000002b8e8000 CR4: 00000000003506f0 DR0: 0000200000000180 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: <IRQ> orc_find arch/x86/kernel/unwind_orc.c:211 [inline] unwind_next_frame+0x217/0x2970 arch/x86/kernel/unwind_orc.c:494 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 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+0x153/0x950 kernel/rcu/tree.c:2837 inet_frag_destroy+0x1f4/0x290 net/ipv4/inet_fragment.c:309 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:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010 Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 a1 ea cb f6 e8 4c fd fc f6 fb bf 01 00 00 00 <e8> f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f RSP: 0018:ffffc900196f7be0 EFLAGS: 00000282 RAX: 07e9e1974f456f00 RBX: 0000000000000000 RCX: 07e9e1974f456f00 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc900196f7c80 R08: ffffffff911cd5ff R09: 1ffffffff2239abf R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920032def7c irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__do_sys_perf_event_open kernel/events/core.c:12960 [inline] RIP: 0010:__se_sys_perf_event_open+0x1843/0x1c50 kernel/events/core.c:12609 Code: 85 02 03 00 00 48 8b 74 24 20 8b 96 fc 02 00 00 48 8b 5c 24 28 48 89 df e8 ba 3f 00 00 48 89 df e8 92 3a ff ff 48 8b 7c 24 48 <e8> 28 af e1 08 80 7c 24 17 00 74 07 e8 dc e9 d7 ff eb 4b e8 d5 e9 RSP: 0018:ffffc900196f7d40 EFLAGS: 00000246 RAX: 07e9e1974f456f00 RBX: ffff88801eb0e400 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffff88801eb0e440 RBP: ffffc900196f7f10 R08: ffffffff911cd5ff R09: 1ffffffff2239abf R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: 0000000000000000 R13: 1ffff920032defb8 R14: ffff88805a130e60 R15: ffff88807d9f3c00 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: 0033:0x7faa93f9ce59 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:00007faa94e18028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007faa94215fa0 RCX: 00007faa93f9ce59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000003c0 RBP: 00007faa94032d6f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007faa94216038 R14: 00007faa94215fa0 R15: 00007ffe9c5b8b78 </TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026/06/10 07:14 | linux-6.6.y | 924b4a879cbb | 34dab4be | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-6-6-kasan-perf | INFO: rcu detected stall in __run_timers |