rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=003c/1/0x4000000000000000 softirq=18995/18995 fqs=0
	(detected by 1, t=10506 jiffies, g=22825, q=51 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6648 Comm: syz.2.781 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4738 [inline]
RIP: 0010:__lock_acquire+0x6da/0x7c50 kernel/locking/lockdep.c:4999
Code: 4c 89 e1 41 bc ff ff ff ff 44 0f 4c e0 4c 8d a9 00 0b 00 00 41 ff c4 45 8d 77 01 49 ff cf 44 89 f0 83 c0 fe 0f 88 70 01 00 00 <44> 89 fb 81 e3 ff ff ff 7f 83 f8 31 73 43 48 8d 04 9b 49 8d 5c c5
RSP: 0018:ffffc90000007860 EFLAGS: 00000013
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffff888025038000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff908c8240
RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: 0000000000000000
R13: ffff888025038b00 R14: 0000000000000004 R15: 0000000000000002
FS:  00007f4ca62b26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c308598 CR3: 000000007b4e7000 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
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x6a/0x490 lib/debugobjects.c:698
 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline]
 debug_activate kernel/time/hrtimer.c:503 [inline]
 enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1105
 __run_hrtimer kernel/time/hrtimer.c:1764 [inline]
 __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 6e be 6c 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> 16 44 3d f7 65 8b 05 a7 f1 e7 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003946d20 EFLAGS: 00000206
RAX: 81c8a5b88b08be00 RBX: 0000000000000a02 RCX: 81c8a5b88b08be00
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: 0000000000000001
RBP: ffffc90003946db0 R08: dffffc0000000000 R09: fffffbfff2119074
R10: fffffbfff2119074 R11: 1ffffffff2119073 R12: dffffc0000000000
R13: 0000000000000a02 R14: ffff888054c392e8 R15: 1ffff92000728da4
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 taprio_change+0x4143/0x50f0 net/sched/sch_taprio.c:1689
 qdisc_create+0x7cb/0x1090 net/sched/sch_api.c:1305
 tc_modify_qdisc+0xb2f/0x1cc0 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4ca538f749
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:00007f4ca62b2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4ca55e5fa0 RCX: 00007f4ca538f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f4ca5413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ca55e6038 R14: 00007f4ca55e5fa0 R15: 00007ffd825b8408
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g22825 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=11009
rcu: rcu_preempt kthread starved for 10506 jiffies! g22825 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26880 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6648 Comm: syz.2.781 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0x369/0x7c50 kernel/locking/lockdep.c:4983
Code: e8 ac f0 e9 ff 0f 0b e9 8f 56 00 00 31 c0 48 89 94 24 a8 00 00 00 48 8d 04 80 48 8b 8c 24 88 00 00 00 4c 8d a4 c1 e0 0a 00 00 <48> 8d 8c c1 00 0b 00 00 48 89 4c 24 18 48 c1 e9 03 48 89 4c 24 50
RSP: 0018:ffffc90000007860 EFLAGS: 00000046
RAX: 000000000000000f RBX: ffffffff96c86d28 RCX: ffff888025038000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff96c86d28
RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: 0000000000000001
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: ffff888025038b58
R13: 0000000000000000 R14: ffff888025038b50 R15: 0000000000000000
FS:  00007f4ca62b26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c308598 CR3: 000000007b4e7000 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
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x63/0x340 lib/debugobjects.c:753
 debug_hrtimer_deactivate kernel/time/hrtimer.c:453 [inline]
 debug_deactivate+0x29/0x240 kernel/time/hrtimer.c:509
 __run_hrtimer kernel/time/hrtimer.c:1715 [inline]
 __hrtimer_run_queues+0x2df/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 6e be 6c 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> 16 44 3d f7 65 8b 05 a7 f1 e7 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003946d20 EFLAGS: 00000206
RAX: 81c8a5b88b08be00 RBX: 0000000000000a02 RCX: 81c8a5b88b08be00
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: 0000000000000001
RBP: ffffc90003946db0 R08: dffffc0000000000 R09: fffffbfff2119074
R10: fffffbfff2119074 R11: 1ffffffff2119073 R12: dffffc0000000000
R13: 0000000000000a02 R14: ffff888054c392e8 R15: 1ffff92000728da4
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 taprio_change+0x4143/0x50f0 net/sched/sch_taprio.c:1689
 qdisc_create+0x7cb/0x1090 net/sched/sch_api.c:1305
 tc_modify_qdisc+0xb2f/0x1cc0 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4ca538f749
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:00007f4ca62b2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4ca55e5fa0 RCX: 00007f4ca538f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f4ca5413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ca55e6038 R14: 00007f4ca55e5fa0 R15: 00007ffd825b8408
 </TASK>