syzbot

 sign-in | mailing list | source | docs
🐞 Open [460]
🐞 Fixed [21]
🐞 Invalid [171]
⬇ Missing Backports [18]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in perf_event_open (2)

Status: upstream: reported C repro on 2025/11/10 01:14
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+87408f570c7f21d4f57d@syzkaller.appspotmail.com
First crash: 129d, last: 8d09h
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/11/14 linux-6.6.y (ToT) 0a805b6ea8cd C [report] INFO: rcu detected stall in perf_event_open
2025/11/14 upstream (ToT) d4f8cccc6230 C Didn't crash
▶ ▼ Similar bugs (17)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in sys_perf_event_open (2) origin:lts-only 1 C error 73 7d10h 799d 0/3 upstream: reported C repro on 2024/01/09 18:19
upstream INFO: rcu detected stall in perf_event_open (2) perf 1 1 1633d 1633d 0/29 auto-closed as invalid on 2021/11/26 20:49
upstream INFO: rcu detected stall in perf_event_open kernel 1 1 1730d 1730d 0/29 auto-closed as invalid on 2021/09/21 01:14
linux-6.1 INFO: rcu detected stall in sys_perf_event_open (2) origin:lts-only 1 C done 44 8d13h 542d 0/3 upstream: reported C repro on 2024/09/23 05:55
linux-6.6 INFO: rcu detected stall in perf_event_open 1 C done 4 203d 216d 2/2 fixed on 2025/10/06 10:09
upstream BUG: soft lockup in perf_event_open (2) net virt 1 8 5d04h 11d 0/29 upstream: reported on 2026/03/08 04:57
upstream BUG: soft lockup in perf_event_open trace bpf 1 2 266d 263d 0/29 auto-obsoleted due to no activity on 2025/09/23 09:29
upstream INFO: rcu detected stall in __se_sys_perf_event_open perf 1 1 2084d 2084d 0/29 auto-closed as invalid on 2020/10/02 02:08
upstream INFO: rcu detected stall in sys_perf_event_open (3) perf 1 1 2262d 2262d 0/29 closed as invalid on 2020/01/08 05:23
upstream INFO: rcu detected stall in sys_perf_event_open (4) perf 1 1 2262d 2261d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in sys_perf_event_open (2) perf 1 8 2296d 2298d 0/29 closed as invalid on 2019/12/04 14:14
linux-6.1 INFO: rcu detected stall in sys_perf_event_open 1 1 646d 646d 0/3 auto-obsoleted due to no activity on 2024/09/19 01:45
linux-5.15 INFO: rcu detected stall in sys_perf_event_open 1 1 1065d 1065d 0/3 auto-obsoleted due to no activity on 2023/08/17 04:33
upstream INFO: rcu detected stall in sys_perf_event_open perf 1 1 2741d 2739d 0/29 auto-closed as invalid on 2019/03/14 17:19
android-5-15 BUG: soft lockup in sys_perf_event_open 1 1 682d 682d 0/2 auto-obsoleted due to no activity on 2024/08/04 07:07
upstream BUG: soft lockup in sys_perf_event_open perf 1 1 657d 653d 0/29 auto-obsoleted due to no activity on 2024/08/29 01:52
upstream BUG: soft lockup in sys_perf_event_open (2) kvm fs 1 6 425d 532d 0/29 auto-obsoleted due to no activity on 2025/04/18 04:31
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/01/15 04:44 2h33m fix candidate upstream OK (0) job log

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10086 ticks this GP) idle=49fc/1/0x4000000000000000 softirq=11224/16370 fqs=4640
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1498168         14            0
rcu: 	cputime:    14166      38312           41   ==> 52480(ms)
rcu: 	(t=10500 jiffies g=8789 q=1914 ncpus=2)
CPU: 1 PID: 5934 Comm: syz.0.22 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:seqcount_lockdep_reader_access+0x17f/0x1c0 include/linux/seqlock.h:105
Code: 00 4d 85 e4 75 16 e8 90 90 0f 00 eb 15 e8 89 90 0f 00 e8 14 77 f1 08 4d 85 e4 74 ea e8 7a 90 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc900001ef400 EFLAGS: 00000246
RAX: ffffffff81760046 RBX: 0000000000000000 RCX: ffff8880761d5a00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001ef4b8 R08: ffffffff90d9460f R09: 1ffffffff21b28c1
R10: dffffc0000000000 R11: fffffbfff21b28c2 R12: 0000000000000200
R13: 000001fb7086095e R14: 1ffff9200003de80 R15: dffffc0000000000
FS:  000055555a2ad500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000028dbc000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 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+0x34a/0x4e0 net/core/dev.c:5115
 __netif_rx+0x78/0xc0 net/core/dev.c:5158
 veth_forward_skb drivers/net/veth.c:321 [inline]
 veth_xmit+0x550/0x9f0 drivers/net/veth.c:374
 __netdev_start_xmit include/linux/netdevice.h:4943 [inline]
 netdev_start_xmit include/linux/netdevice.h:4957 [inline]
 xmit_one net/core/dev.c:3619 [inline]
 dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635
 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425
 dev_queue_xmit include/linux/netdevice.h:3113 [inline]
 br_dev_queue_push_xmit+0x6a6/0x850 net/bridge/br_forward.c:53
 NF_HOOK+0x613/0x6a0 include/linux/netfilter.h:304
 br_nf_post_routing+0xb41/0xfb0 net/bridge/br_netfilter_hooks.c:977
 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+0x213/0x3d0 include/linux/netfilter.h:302
 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline]
 br_nf_forward_finish+0xa33/0xe50 net/bridge/br_netfilter_hooks.c:684
 NF_HOOK+0x613/0x6a0 include/linux/netfilter.h:304
 br_nf_forward_ip+0xcc1/0x1110 net/bridge/br_netfilter_hooks.c:754
 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+0x213/0x3d0 include/linux/netfilter.h:302
 __br_forward+0x41f/0x600 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x143d/0x1950 net/bridge/br_input.c:215
 br_nf_hook_thresh+0x3b6/0x480 net/bridge/br_netfilter_hooks.c:1184
 br_nf_pre_routing_finish_ipv6+0x9e3/0xd90 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:304 [inline]
 br_nf_pre_routing_ipv6+0x34d/0x680 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
 br_handle_frame+0x957/0x14c0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf6b/0x3ac0 net/core/dev.c:5502
 __netif_receive_skb_one_core net/core/dev.c:5606 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5722
 process_backlog+0x380/0x6e0 net/core/dev.c:6050
 __napi_poll+0xc0/0x460 net/core/dev.c:6612
 napi_poll net/core/dev.c:6679 [inline]
 net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
 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+0xc7/0x190 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+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0a d9 1a f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e2 53 ea f6 65 8b 05 d3 9a 92 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc900035475e0 EFLAGS: 00000206
RAX: a5cde8297fe06900 RBX: 0000000000000a02 RCX: a5cde8297fe06900
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffffc90003547678 R08: ffffffff90d9460f R09: 1ffffffff21b28c1
R10: dffffc0000000000 R11: fffffbfff21b28c2 R12: dffffc0000000000
R13: ffff888072972ef0 R14: ffffffff8d3eb7c0 R15: 1ffff920006a8ebc
 __stack_depot_save+0x560/0x630 lib/stackdepot.c:439
 save_stack+0x105/0x1f0 mm/page_owner.c:129
 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 mm_free_pgd kernel/fork.c:809 [inline]
 __mmdrop+0xb4/0x3d0 kernel/fork.c:925
 mmdrop include/linux/sched/mm.h:54 [inline]
 mmdrop_sched include/linux/sched/mm.h:82 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:109 [inline]
 finish_task_switch+0x3e0/0x920 kernel/sched/core.c:5279
 context_switch kernel/sched/core.c:5383 [inline]
 __schedule+0x14da/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194
 __do_sys_perf_event_open kernel/events/core.c:12916 [inline]
 __se_sys_perf_event_open+0x1802/0x1c20 kernel/events/core.c:12567
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc6a278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc3b7a13f8 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc6a29e5fa0 RCX: 00007fc6a278f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007fc6a2813f91 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6a29e5fa0 R14: 00007fc6a29e5fa0 R15: 0000000000000005
 </TASK>

Crashes (42):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/12 15:29 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/11/11 19:51 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/03/10 23:46 linux-6.6.y 4fc00fe35d46 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/03/08 08:09 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/03/07 22:14 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/03/07 18:17 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/21 23:45 linux-6.6.y 7a137e9bfa0e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/16 23:52 linux-6.6.y ae462074fde3 5d52cba5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/16 06:00 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/15 16:01 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/14 22:36 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/13 16:59 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/11 10:34 linux-6.6.y c56aaf1a85ae 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/02/04 10:21 linux-6.6.y 2cf6f68313dc 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/30 17:58 linux-6.6.y 2cf6f68313dc ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/26 14:49 linux-6.6.y cbb31f77b879 a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/24 06:25 linux-6.6.y cbb31f77b879 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/23 05:20 linux-6.6.y cbb31f77b879 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/19 02:02 linux-6.6.y cbb31f77b879 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/13 00:13 linux-6.6.y c596736dadab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/10 09:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/10 00:48 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/09 11:24 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/06 16:26 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/06 05:25 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/03 09:33 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/01 07:12 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2026/01/01 02:38 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/27 10:00 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/24 19:31 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/23 06:06 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/19 17:44 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/16 18:50 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/15 22:58 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/13 21:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/13 07:15 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/12 21:42 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/11 03:07 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/05 06:01 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/12/05 00:42 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/11/11 15:21 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
2025/11/10 01:14 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in perf_event_open
* Struck through repros no longer work on HEAD.