rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 ticks this GP) idle=d44c/1/0x4000000000000000 softirq=21376/21376 fqs=60
rcu: (detected by 0, t=10502 jiffies, g=15861, q=1152 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6514 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_atomic_set arch/x86/include/asm/atomic.h:28 [inline]
RIP: 0010:raw_atomic_set include/linux/atomic/atomic-arch-fallback.h:503 [inline]
RIP: 0010:atomic_set include/linux/atomic/atomic-instrumented.h:68 [inline]
RIP: 0010:taprio_set_budgets+0x274/0x3b0 net/sched/sch_taprio.c:678
Code: 89 ef be 04 00 00 00 e8 aa cf c4 f8 48 8b 44 24 28 48 8d 3c 18 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 0f 85 bd 00 00 00 44 89 6d 00 48 39 5c 24 20 0f 84 e5 00 00
RSP: 0018:ffffc90000a08c00 EFLAGS: 00000802
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88807a0b6080
RBP: ffff88807a0b6080 R08: ffff88807a0b6083 R09: 1ffff1100f416c10
R10: dffffc0000000000 R11: ffffed100f416c11 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88807c04c2a0 R15: ffff88807a0b6000
FS: 00007fa2d5ff66c0(0000) GS:ffff8881261ea000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 000000007e738000 CR4: 00000000003526f0
Call Trace:
advance_sched+0x963/0xc90 net/sched/sch_taprio.c:983
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc20 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3d0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lockdep_unregister_key+0x2e2/0x360 kernel/locking/lockdep.c:6616
Code: 9d 00 00 00 89 c6 48 c7 c7 70 98 7b 95 e8 f6 ad a1 09 90 e9 44 fe ff ff e8 db fd 9e 09 41 f7 c6 00 02 00 00 74 a5 fb 40 84 ed <75> a4 eb b5 0f 0b e9 1a ff ff ff 0f 0b e9 24 ff ff ff e8 17 e3 ec
RSP: 0018:ffffc90003007090 EFLAGS: 00000246
RAX: 0000000000000046 RBX: ffff888027dafa68 RCX: 0000000000000046
RDX: ffffffff933713d8 RSI: ffffffff8d75fc34 RDI: ffffffff8bc082e0
RBP: ffff8880295fbd00 R08: ffffffff8df3f980 R09: ffffffff81aacee8
R10: dffffc0000000000 R11: fffffbfff1efa90f R12: 0000000000000000
R13: ffff888027dafa69 R14: 0000000000000246 R15: ffffffff937713f8
__qdisc_destroy+0x166/0x3f0 net/sched/sch_generic.c:1079
taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2161
qdisc_graft+0x1173/0x1580 net/sched/sch_api.c:1162
__tc_modify_qdisc net/sched/sch_api.c:1761 [inline]
tc_modify_qdisc+0x16d3/0x2020 net/sched/sch_api.c:1817
rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6967
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x812/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x530/0x850 net/socket.c:2592
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x8a/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa2d698f749
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:00007fa2d5ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa2d6be5fa0 RCX: 00007fa2d698f749
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000005
RBP: 00007fa2d6a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa2d6be6038 R14: 00007fa2d6be5fa0 R15: 00007ffe9c2b7448
rcu: rcu_preempt kthread starved for 10205 jiffies! g15861 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27472 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fb0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1520 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x890 kernel/kthread.c:463
ret_from_fork+0x50c/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6216 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1240 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 f4 8c 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 9f 88 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 83 88
RSP: 0000:ffffc90003ecf840 EFLAGS: 00000293
RAX: ffffffff81b4a69d RBX: 1ffff11017128129 RCX: ffff88807e8e9e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003ecf970 R08: ffffffff8f7d4877 R09: 1ffffffff1efa90e
R10: dffffc0000000000 R11: fffffbfff1efa90f R12: ffff8880b8940948
R13: dffffc0000000000 R14: ffff8880b883bac0 R15: 0000000000000001
FS: 00007f1b9b98f880(0000) GS:ffff8881260ea000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ccb1c2b568 CR3: 000000001df20000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x5fe/0x1150 arch/x86/mm/tlb.c:1472
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103
wp_page_copy mm/memory.c:3785 [inline]
do_wp_page+0x1bb1/0x57d0 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x1544/0x3170 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x6d/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f1b9b2b5b69
Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff14d2e7f0 EFLAGS: 00010202
RAX: 00007f1b9b3f21d0 RBX: 000055ccb1c2b540 RCX: 000055ccb1c2b540
RDX: 000055ccb1c2b540 RSI: 00007f1b9b3f21d0 RDI: 000055ccb1c2b540
RBP: 00007f1b9b3f1ac0 R08: 0000000000002760 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000049c0
R13: 000055ccb1c2ff00 R14: 0000000000000380 R15: 00007f1b9b3f1ac0