syzbot


INFO: rcu detected stall in perf_release (2)

Status: upstream: reported syz repro on 2025/10/08 16:52
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+f77a0cb07d77ae1c531e@syzkaller.appspotmail.com
First crash: 17d, last: 17d
Bug presence (2)
Date Name Commit Repro Result
2025/10/12 linux-6.1.y (ToT) 882efbdd9d34 syz [report] INFO: rcu detected stall in futex
2025/10/12 upstream (ToT) 3a8660878839 syz Didn't crash
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in perf_release 1 2 404d 404d 0/3 auto-obsoleted due to no activity on 2024/12/25 21:00
linux-6.6 INFO: rcu detected stall in perf_release 1 C done 1 59d 59d 2/2 fixed on 2025/10/06 10:09
upstream INFO: rcu detected stall in perf_release mm cgroups 1 19 2153d 2173d 0/29 auto-closed as invalid on 2020/03/03 09:44
android-5-15 BUG: soft lockup in perf_release (2) 1 1 210d 210d 0/2 auto-obsoleted due to no activity on 2025/06/27 12:18
android-5-15 BUG: soft lockup in perf_release 1 3 491d 554d 0/2 auto-obsoleted due to no activity on 2024/09/19 17:30

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2632 jiffies s: 17121 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8318 Comm: syz.1.3668 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__lock_acquire+0x246/0x7c50 kernel/locking/lockdep.c:4959
Code: 30 0f 87 8b 65 00 00 4f 8d 74 e6 f8 4c 89 f0 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 00 66 00 00 48 8b 44 24 60 48 83 7d 10 00 <0f> 84 01 01 00 00 45 8b 26 44 89 e1 81 e1 ff 1f 00 00 48 8b 44 24
RSP: 0018:ffffc90000006fe0 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffffffff8cb2abe0 RCX: ffffffff96be9103
RDX: 000000000000002c RSI: 0000000000000000 RDI: ffffffff8cb2abe0
RBP: ffffc90000007230 R08: dffffc0000000000 R09: 0000000000000001
R10: fffffbfff1c3ecb6 R11: 1ffffffff1c3ecb5 R12: 000000000000000a
R13: 0000000000000000 R14: ffff88807bb6e468 R15: 000000000000002c
FS:  0000555579eea500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30f63fff CR3: 000000007fa2d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 __perf_event_output kernel/events/core.c:7728 [inline]
 perf_event_output_forward+0xb7/0x2a0 kernel/events/core.c:7750
 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
 perf_tp_event+0x335/0xb60 kernel/events/core.c:10029
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10002
 perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x84/0x500 kernel/rcu/tree_plugin.h:685
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 2d 97 96 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900000079c0 EFLAGS: 00000206
RAX: c6bda4dd69ac8100 RBX: 1ffff92000000f40 RCX: c6bda4dd69ac8100
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: ffffffff8adefd20
RBP: ffffc90000007ac0 R08: dffffc0000000000 R09: fffffbfff215c46c
R10: fffffbfff215c46c R11: 1ffffffff215c46b R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 process_backlog+0x3ff/0x6e0 net/core/dev.c:6024
 __napi_poll+0xc0/0x460 net/core/dev.c:6590
 napi_poll net/core/dev.c:6657 [inline]
 net_rx_action+0x5b1/0xad0 net/core/dev.c:6771
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__list_del include/linux/list.h:114 [inline]
RIP: 0010:__list_del_entry include/linux/list.h:137 [inline]
RIP: 0010:list_del_init include/linux/list.h:206 [inline]
RIP: 0010:perf_remove_from_owner+0x2ee/0x490 kernel/events/core.c:5149
Code: 45 00 48 89 44 24 08 4c 8d 70 08 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 52 56 2e 00 <4d> 89 3e 4c 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 80
RSP: 0018:ffffc9000385fc28 EFLAGS: 00000246
RAX: 1ffff1100f76ddc2 RBX: 1ffff110048a81e0 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8adefd00 RDI: ffff888024540ef8
RBP: ffff888024540ef0 R08: dffffc0000000000 R09: fffffbfff1c3ecb6
R10: fffffbfff1c3ecb6 R11: 1ffffffff1c3ecb5 R12: ffff88807bb6d940
R13: ffff888024540f00 R14: ffff88807bb6ee10 R15: ffff8880734038f0
 perf_event_release_kernel+0x130/0x8c0 kernel/events/core.c:5187
 perf_release+0x37/0x40 kernel/events/core.c:5297
 __fput+0x22c/0x920 fs/file_table.c:320
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f120478eec9
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:00007ffc5a1ee098 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000042ef3 RCX: 00007f120478eec9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 000000025a1ee38f
R10: 0000001b30320000 R11: 0000000000000246 R12: 00007f12049e5fac
R13: 00007f12049e5fa0 R14: ffffffffffffffff R15: 0000000000000005
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/08 16:51 linux-6.1.y 882efbdd9d34 7e2882b3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in perf_release
* Struck through repros no longer work on HEAD.