rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (5 ticks this GP) idle=05fc/1/0x4000000000000000 softirq=90791/90791 fqs=9
rcu: 	(detected by 1, t=10502 jiffies, g=77689, q=1267 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21915 Comm: syz.4.4556 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lock_release+0xd/0x3b0 kernel/locking/lockdep.c:5876
Code: 2f 00 00 00 e9 0e ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 <53> 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 20 f1 e1 10 48 89 44
RSP: 0018:ffffc90000007ac0 EFLAGS: 00000006
RAX: ffffffff8970671c RBX: ffffffff89706658 RCX: ffff88804d9a8000
RDX: 0000000000010100 RSI: ffffffff89706658 RDI: ffffffff8df41aa0
RBP: 0000000000000001 R08: ffff88806413d19f R09: 1ffff1100c827a33
R10: dffffc0000000000 R11: ffffed100c827a34 R12: ffff88806413d320
R13: ffff88806413d000 R14: 1886c783875a2800 R15: ffff88807c286000
FS:  00007fcd983da6c0(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2405f9 CR3: 0000000075d88000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:993
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x51c/0xc30 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+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:312 [inline]
RIP: 0010:handle_softirqs+0x161/0x7c0 kernel/softirq.c:610
Code: 89 6c 24 20 0f b7 db 48 c7 c7 60 d8 69 8b e8 d6 79 d4 09 65 66 c7 05 74 dd fa 10 00 00 e8 57 8c 43 00 fb 48 c7 c5 c0 c0 c0 8d <b8> ff ff ff ff 0f bc c3 41 89 c6 41 ff c6 0f 84 85 03 00 00 89 5c
RSP: 0018:ffffc90000007f40 EFLAGS: 00000206
RAX: 0000000000001b0c RBX: 0000000000000386 RCX: 0000000000000102
RDX: 0000000000000003 RSI: ffffffff8d792055 RDI: ffffffff8bc083e0
RBP: ffffffff8dc0c0c0 R08: ffffffff8f822277 R09: 1ffffffff1f0444e
R10: dffffc0000000000 R11: fffffbfff1f0444f R12: 0000000000000000
R13: 0000000000000000 R14: ffff88804d9a8000 R15: 0000000000000000
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:kasan_check_range+0x1dc/0x2c0 mm/kasan/generic.c:200
Code: 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 cc cc cc cc cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 5f 41
RSP: 0018:ffffc9000bc5f2b0 EFLAGS: 00000256
RAX: 0000000000000001 RBX: ffff8880b8640b40 RCX: ffffffff819e91ce
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880b8640b40
RBP: ffffc9000bc5f358 R08: ffff8880b8640b43 R09: 1ffff110170c8168
R10: dffffc0000000000 R11: ffffed10170c8169 R12: 1ffff9200178be58
R13: 0000000000000981 R14: ffffc9000bc5f2e0 R15: dffffc0000000000
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
 queued_spin_trylock include/asm-generic/qspinlock.h:97 [inline]
 do_raw_spin_trylock+0x9e/0x180 kernel/locking/spinlock_debug.c:123
 __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
 _raw_spin_trylock+0x21/0x80 kernel/locking/spinlock.c:138
 spin_trylock include/linux/spinlock.h:361 [inline]
 rmqueue_pcplist mm/page_alloc.c:3330 [inline]
 rmqueue mm/page_alloc.c:3371 [inline]
 get_page_from_freelist+0x6ea/0x2580 mm/page_alloc.c:3912
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
 vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
 folio_prealloc+0x30/0x180 mm/memory.c:-1
 alloc_anon_folio mm/memory.c:5165 [inline]
 do_anonymous_page mm/memory.c:5222 [inline]
 do_pte_missing+0x14e8/0x3330 mm/memory.c:4399
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1650/0x29f0 mm/gup.c:1428
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
 __mm_populate+0x24c/0x380 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd9758f749
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:00007fcd983da038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fcd977e5fa0 RCX: 00007fcd9758f749
RDX: b80393884f01a506 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fcd97613f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000004008032 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcd977e6038 R14: 00007fcd977e5fa0 R15: 00007fffbc162a68
 </TASK>
rcu: rcu_preempt kthread starved for 7405 jiffies! g77689 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27480 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 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+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 21548 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+0xcca/0x1260 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 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 73 93 0b 00 eb e4 44
RSP: 0000:ffffc90002e67820 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170c856d RCX: ffff888025090000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e67950 R08: ffffffff8f822277 R09: 1ffffffff1f0444e
R10: dffffc0000000000 R11: fffffbfff1f0444f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS:  00007ff9eaf57880(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560b42a0a568 CR3: 0000000053b90000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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+0x60a/0x1170 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+0x1bb1/0x5810 mm/memory.c:4180
 handle_pte_fault mm/memory.c:6289 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x14c5/0x32b0 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+0x71/0xd0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7ff9ea8b5b69
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:00007ffcc29b7d50 EFLAGS: 00010202
RAX: 00007ff9ea9f21d0 RBX: 0000560b42a0a540 RCX: 0000560b42a0a540
RDX: 0000560b42a0a540 RSI: 00007ff9ea9f21d0 RDI: 0000560b42a0a540
RBP: 00007ff9ea9f1ac0 R08: 0000000000002760 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000049c0
R13: 0000560b42a0ef00 R14: 00000000000003e0 R15: 00007ff9ea9f1ac0
 </TASK>