syzbot


INFO: rcu detected stall in perf_release

Status: upstream: reported syz repro on 2025/11/02 03:41
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+8ed55d909a092bca9174@syzkaller.appspotmail.com
First crash: 70d, last: 17d
Bug presence (2)
Date Name Commit Repro Result
2025/11/02 linux-5.15.y (ToT) cc5ec8769306 syz [report] INFO: rcu detected stall in corrupted
2025/11/02 upstream (ToT) 691d401c7e0e syz Didn't crash
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in perf_release (2) origin:lts-only 1 C 1 7d17h 7d17h 0/2 upstream: reported C repro on 2026/01/03 14:19
linux-6.1 INFO: rcu detected stall in perf_release 1 2 481d 481d 0/3 auto-obsoleted due to no activity on 2024/12/25 21:00
linux-6.1 INFO: rcu detected stall in perf_release (2) 1 C inconclusive 3 44d 94d 0/3 upstream: reported C repro on 2025/10/08 16:52
linux-6.6 INFO: rcu detected stall in perf_release 1 C done 1 136d 136d 2/2 fixed on 2025/10/06 10:09
upstream INFO: rcu detected stall in perf_release mm cgroups 1 19 2229d 2250d 0/29 auto-closed as invalid on 2020/03/03 09:44
android-5-15 BUG: soft lockup in perf_release (2) 1 1 287d 287d 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 568d 631d 0/2 auto-obsoleted due to no activity on 2024/09/19 17:30
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/01/08 07:53 15m retest repro linux-5.15.y report log
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/12/13 13:46 16m fix candidate upstream error job log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=ba7/1/0x4000000000000002 softirq=22512/22513 fqs=5191 
	(detected by 1, t=10502 jiffies, g=36617, q=235251)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7713 Comm: syz.2.3218 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_release kernel/locking/lockdep.c:5311 [inline]
RIP: 0010:lock_release+0x244/0x870 kernel/locking/lockdep.c:5643
Code: e8 03 42 0f b6 04 28 84 c0 0f 85 94 04 00 00 41 83 3e 00 0f 85 ca 03 00 00 4d 8d 74 24 20 4c 89 f3 48 c1 eb 03 42 0f b6 04 2b <84> c0 4c 8b 7c 24 20 0f 85 90 04 00 00 41 8b 06 3d 00 00 10 00 72
RSP: 0018:ffffc900000071c0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: 1ffff1100f2898dc RCX: 0000000000000001
RDX: 0000000000000002 RSI: ffffffff8c11c720 RDI: ffff88807944c6c0
RBP: ffffc900000072d0 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: ffff88807944c6c0
R13: dffffc0000000000 R14: ffff88807944c6e0 R15: 0000000000000002
FS:  000055555c747500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34263fff CR3: 000000007470e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __perf_output_begin kernel/events/ring_buffer.c:262 [inline]
 perf_output_begin_forward+0x793/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
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 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: 55f131e3cdd10900 RBX: 1ffff92000000f60 RCX: 55f131e3cdd10900
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 be 9a d2 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> d6 22 a6 f7 65 8b 05 67 20 57 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000d32fac0 EFLAGS: 00000206
RAX: 55f131e3cdd10900 RBX: 0000000000000a02 RCX: 55f131e3cdd10900
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: 0000000000000001
RBP: ffffc9000d32fb58 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff962db060 R15: 1ffff92001a65f58
 debug_object_activate+0x2d2/0x480 lib/debugobjects.c:712
 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline]
 __call_rcu kernel/rcu/tree.c:2995 [inline]
 call_rcu+0xa7/0x930 kernel/rcu/tree.c:3091
 put_event kernel/events/core.c:5258 [inline]
 perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5383
 perf_release+0x37/0x40 kernel/events/core.c:5393
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc5bb2b2749
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:00007ffcd14a2478 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000070469 RCX: 00007fc5bb2b2749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 00000001d14a276f
R10: 0000001b33320000 R11: 0000000000000246 R12: 00007fc5bb508fac
R13: 00007fc5bb508fa0 R14: ffffffffffffffff R15: 0000000000000005
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/24 17:25 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in perf_release
2025/11/02 03:40 linux-5.15.y cc5ec8769306 2c50b6a9 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in perf_release
* Struck through repros no longer work on HEAD.