[v5.15] INFO: rcu detected stall in irqentry_exit (2)

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Sep 16, 2025, 10:07:33 AM (3 days ago) Sep 16
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Hello,

syzbot found the following issue on:

HEAD commit: 43bb85222e53 Linux 5.15.193
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1468b762580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=052866219c84faa6fcbe
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0bc183664ae8/disk-43bb8522.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0fc2f6618934/vmlinux-43bb8522.xz
kernel image: https://storage.googleapis.com/syzbot-assets/af70b3957f4c/bzImage-43bb8522.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+052866...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-....: (568 ticks this GP) idle=a37/1/0x4000000000000002 softirq=6911/6911 fqs=2234
(detected by 1, t=10505 jiffies, g=8161, q=1945)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4461 Comm: syz.4.48 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 c9 f1 0b 48 89 de 5b e9 47 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 94 a4 8a 7e 65 8b 15 95 a4 8a 7e 81 e2 00
RSP: 0018:ffffc90000007318 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc900000074c0 RCX: ffff888029f23b80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007410 R08: dffffc0000000000 R09: ffffc90000007460
R10: fffff52000000e93 R11: 1ffff92000000e8c R12: dffffc0000000000
R13: ffffc900000074c6 R14: 0000000000000000 R15: ffffc90000007680
FS: 00007fc07d66b6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc07d628f98 CR3: 000000005f714000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
perf_prepare_sample+0x6e9/0x1cb0 kernel/events/core.c:7665
__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 ad 13 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: 5c9869e378cc6d00 RBX: 1ffff92000000f60 RCX: 5c9869e378cc6d00
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8c120b00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:771 [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:1690 [inline]
__hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754
hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1771
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:preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6799
Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 70 bf 01 00 00 00 e8 9f 37 a0 f7 e8 9a b0 cc f7 fb bf 01 00 00 00 <e8> ef b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc90002fffda0 EFLAGS: 00000286
RAX: 5c9869e378cc6d00 RBX: 0000000000000000 RCX: 5c9869e378cc6d00
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: 0000000000000001
RBP: ffffc90002fffe40 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920005fffb4
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x2a/0x70 kernel/entry/common.c:114
Code: 41 56 53 48 89 f3 49 89 fe 48 8b 7c 24 10 e8 3d f6 ff ff eb 31 eb 35 e8 c4 f1 d4 f7 e8 bf ef d4 f7 fb 65 48 8b 05 26 76 59 76 <48> 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 51 32 bd f7 48
RSP: 0018:ffffc90002ffff08 EFLAGS: 00000286
RAX: ffff888029f23b80 RBX: 000000000000002e RCX: 5c9869e378cc6d00
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc90002ffff48 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc90002ffff58 R15: 0000000000000000
do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc07f403ba9
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:00007fc07d66b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc07f64afa0 RCX: 00007fc07f403ba9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 000000000000002e
RBP: 00007fc07f486e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc07f64b038 R14: 00007fc07f64afa0 R15: 00007fff816e6608
</TASK>


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