Hello,
syzbot found the following issue on:
HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=16cfabcd980000
kernel config:
https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link:
https://syzkaller.appspot.com/bug?extid=8ed55d909a092bca9174
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=1491e32f980000
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+8ed55d...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-....: (1 GPs behind) idle=8bb/1/0x4000000000000002 softirq=20501/20503 fqs=2100
(detected by 1, t=10503 jiffies, g=33281, q=257736)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7393 Comm: syz.0.2934 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:perf_prepare_sample+0x1af/0x1cb0 kernel/events/core.c:7626
Code: be 6a ff 48 89 c3 4d 8d 77 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 db ea 25 00 49 89 1e 4c 8b 74 24 20 eb 05 <e8> 2c 82 e1 ff 4c 89 f6 48 83 e6 20 31 ff e8 fe 85 e1 ff 4c 89 f0
RSP: 0018:ffffc90000006fe0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc90000007180 RCX: ffff888023035940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000070d0 R08: dffffc0000000000 R09: ffffc90000007120
R10: fffff52000000e2b R11: 1ffff92000000e24 R12: dffffc0000000000
R13: ffffc90000007186 R14: 0000000000000000 R15: ffffc90000007340
FS: 0000555571b0f500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c63fff CR3: 0000000078bc4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__perf_event_output kernel/events/core.c:7802 [inline]
perf_event_output_forward+0x146/0x280 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:ffffc900000077a0 EFLAGS: 00000206
RAX: 3cd8863c20533300 RBX: 1ffff92000000ef8 RCX: 3cd8863c20533300
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff7c3d
R10: fffffbfff1ff7c3d R11: 1ffffffff1ff7c3c 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]
ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521
addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
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 de 0d cb 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> f6 95 9e f7 65 8b 05 87 93 4f 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90005bbfac0 EFLAGS: 00000206
RAX: 3cd8863c20533300 RBX: 0000000000000a02 RCX: 3cd8863c20533300
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001
RBP: ffffc90005bbfb58 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff96331cd0 R15: 1ffff92000b77f58
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: 0033:0x7f0246a87fc9
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:00007ffc26a64818 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000005da5d RCX: 00007f0246a87fc9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000126a64b0f
R10: 0000001b33020000 R11: 0000000000000246 R12: 00007f0246cdefac
R13: 00007f0246cdefa0 R14: ffffffffffffffff R15: 0000000000000005
</TASK>
---
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