[v6.6] INFO: rcu detected stall in perf_event_open (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0a805b6ea8cd Linux 6.6.116
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15b5ea92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=87408f570c7f21d4f57d
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/743e52c6a2c2/disk-0a805b6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b7385817c222/vmlinux-0a805b6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/587fbfb2961d/bzImage-0a805b6e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87408f...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (10486 ticks this GP) idle=71ac/1/0x4000000000000000 softirq=21055/21061 fqs=4983
rcu: hardirqs softirqs csw/system
rcu: number: 1195075 0 0
rcu: cputime: 18565 33914 33 ==> 52490(ms)
rcu: (t=10501 jiffies g=25297 q=1825 ncpus=2)
CPU: 0 PID: 7944 Comm: syz.2.718 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:queue_work_on+0x187/0x1e0 kernel/workqueue.c:1840
Code: 4d 85 e4 75 16 e8 39 2c 2f 00 eb 15 e8 32 2c 2f 00 e8 4d 6a 18 09 4d 85 e4 74 ea e8 23 2c 2f 00 fb 48 c7 44 24 20 0e 36 e0 45 <48> b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00 00 00 66 41 c7
RSP: 0018:ffffc900000073a0 EFLAGS: 00000246
RAX: ffffffff8156636d RBX: 0000000000000000 RCX: ffff888027258000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007480 R08: ffffffff90da85f7 R09: 1ffffffff21b50be
R10: dffffc0000000000 R11: fffffbfff21b50bf R12: 0000000000000200
R13: 1ffff92000000e78 R14: 0000000000000000 R15: ffff88801d740001
FS: 00007fa8bfa686c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb8168c2627 CR3: 000000002dda9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
__ieee80211_queue_skb_to_iface net/mac80211/rx.c:232 [inline]
ieee80211_queue_skb_to_iface net/mac80211/rx.c:243 [inline]
ieee80211_rx_h_mgmt+0x4f8/0x6f0 net/mac80211/rx.c:3989
ieee80211_rx_handlers+0x64f0/0xb0c0 net/mac80211/rx.c:4147
ieee80211_invoke_rx_handlers net/mac80211/rx.c:4177 [inline]
ieee80211_prepare_and_rx_handle+0x25fe/0x61d0 net/mac80211/rx.c:5035
ieee80211_rx_for_interface net/mac80211/rx.c:5120 [inline]
__ieee80211_rx_handle_packet net/mac80211/rx.c:5293 [inline]
ieee80211_rx_list+0x26c9/0x2fe0 net/mac80211/rx.c:5428
ieee80211_rx_napi+0x1aa/0x3c0 net/mac80211/rx.c:5451
ieee80211_rx include/net/mac80211.h:4971 [inline]
ieee80211_handle_queued_frames+0x106/0x1a0 net/mac80211/main.c:319
tasklet_action_common+0x2eb/0x4c0 kernel/softirq.c:809
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:preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:7009
Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 63 bf 01 00 00 00 e8 9b 58 e4 f6 e8 06 de 14 f7 fb bf 01 00 00 00 <e8> db b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc9000b8efbc0 EFLAGS: 00000282
RAX: ad861ceea3d6ca00 RBX: 0000000000000000 RCX: ad861ceea3d6ca00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffffc9000b8efc70 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad
R10: dffffc0000000000 R11: fffffbfff1c951ae R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200171df78
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:put_task_struct+0x0/0xc0 include/linux/sched/task.h:125
Code: 80 e1 07 80 c1 03 38 c1 0f 8c d9 fe ff ff 4c 89 f7 e8 84 51 2f 00 e9 cc fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <55> 41 56 53 48 89 fb e8 34 f6 d7 ff 4c 8d 73 28 4c 89 f7 be 04 00
RSP: 0018:ffffc9000b8efd38 EFLAGS: 00000246
RAX: ad861ceea3d6ca00 RBX: ffff888027258000 RCX: 1ffff9200171df94
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888027258000
RBP: ffffc9000b8eff10 R08: ffff8880211fd677 R09: 1ffff1100423face
R10: dffffc0000000000 R11: ffffed100423facf R12: 0000000000000000
R13: 1ffff9200171dfb8 R14: ffff88801ba68848 R15: ffff888027258000
__do_sys_perf_event_open kernel/events/core.c:12922 [inline]
__se_sys_perf_event_open+0x1865/0x1c20 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: 0033:0x7fa8beb8f6c9
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:00007fa8bfa68038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fa8bede5fa0 RCX: 00007fa8beb8f6c9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007fa8bec11f91 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa8bede6038 R14: 00007fa8bede5fa0 R15: 00007ffdd327d258
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 0a805b6ea8cd Linux 6.6.116
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=1395560a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=87408f570c7f21d4f57d
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=1453b0b4580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=164a8914580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/743e52c6a2c2/disk-0a805b6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b7385817c222/vmlinux-0a805b6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/587fbfb2961d/bzImage-0a805b6e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87408f...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU

rcu: 0-....: (10499 ticks this GP) idle=8ffc/1/0x4000000000000000 softirq=12538/12539 fqs=5047
rcu: hardirqs softirqs csw/system
rcu: number: 1518152 0 0
rcu: cputime: 17214 35274 36 ==> 52490(ms)
rcu: (t=10500 jiffies g=11397 q=1236 ncpus=2)
CPU: 0 PID: 5960 Comm: syz.0.17 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025

RIP: 0010:kasan_quarantine_put+0x88/0x220 mm/kasan/quarantine.c:243
Code: e8 8d fc ae ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 80 7a 03 00 45
RSP: 0018:ffffc90000007300 EFLAGS: 00000206
RAX: bb1d5deea0779b01 RBX: ffff8880603e7900 RCX: bb1d5deea0779b00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffff8880603e7900 R08: ffffffff90da85c7 R09: 1ffffffff21b50b8
R10: dffffc0000000000 R11: fffffbfff21b50b9 R12: 0000000000000000
R13: ffffc90000007398 R14: 0000000000080128 R15: 0000000000000286
FS: 00007f7d12c196c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000000100000000 CR3: 000000007847e000 CR4: 00000000003506f0
Call Trace:
<IRQ>
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
skb_kfree_head net/core/skbuff.c:943 [inline]
skb_free_head net/core/skbuff.c:957 [inline]
skb_release_data+0x60a/0x800 net/core/skbuff.c:987
skb_release_all net/core/skbuff.c:1053 [inline]
__kfree_skb net/core/skbuff.c:1067 [inline]
kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1103
dev_kfree_skb_any_reason+0x10c/0x120 net/core/dev.c:3228
free_old_xmit_skbs+0x114/0x3c0 drivers/net/virtio_net.c:791
start_xmit+0x161/0x1420 drivers/net/virtio_net.c:2415
__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
sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:342
__dev_xmit_skb net/core/dev.c:3856 [inline]
__dev_queue_xmit+0x173e/0x35a0 net/core/dev.c:4391
lapb_data_transmit+0x8a/0xa0 net/lapb/lapb_iface.c:447
lapb_transmit_buffer+0x163/0x200 net/lapb/lapb_out.c:149
lapb_t1timer_expiry+0x699/0xab0 net/lapb/lapb_timer.c:-1
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035

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 ea 7c 13 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> f2 f8 e2 f6 65 8b 05 e3 41 8b 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000496fca0 EFLAGS: 00000206
RAX: bb1d5deea0779b00 RBX: 0000000000000a06 RCX: bb1d5deea0779b00

RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001

RBP: ffffc9000496fd30 R08: ffffffff90da8617 R09: 1ffffffff21b50c2
R10: dffffc0000000000 R11: fffffbfff21b50c3 R12: dffffc0000000000
R13: 1ffff9200092dfb8 R14: ffff8880246ae800 R15: 1ffff9200092df94
__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: 0033:0x7f7d11d8f6c9

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:00007f7d12c19038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f7d11fe5fa0 RCX: 00007f7d11d8f6c9
RDX: ffffbfffffffffff RSI: 0000000000000000 RDI: 0000200000000300
RBP: 00007f7d11e11f91 R08: 0000000000000002 R09: 0000000000000000

R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000

R13: 00007f7d11fe6038 R14: 00007f7d11fe5fa0 R15: 00007ffd3df20858
</TASK>


---
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