rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=7d9c/1/0x4000000000000000 softirq=275052/275053 fqs=2
rcu: 	(detected by 0, t=10502 jiffies, g=289065, q=214 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17129 Comm: udevd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213
Code: 64 00 be 03 00 00 00 5b e9 32 53 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 e5 6f 59 12 <48> 8b 34 24 65 48 8b 15 c1 6f 59 12 a9 00 01 ff 00 74 1b f6 c4 01
RSP: 0018:ffffc90000a08918 EFLAGS: 00000002
RAX: 0000000080010102 RBX: ffff888037891300 RCX: ffffffff89c6d447
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888037a02540
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888037891300
R13: ffffffff89c6d300 R14: ffff8880b8528540 R15: ffff8880b8528590
FS:  00007f57e4e4f880(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31b07ff8 CR3: 0000000046df2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000003 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 advance_sched+0x826/0xd20 net/sched/sch_taprio.c:933
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 bf 29 f6 48 89 df e8 9e 0e 2a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 a5 1f 19 f6 65 8b 05 ee 98 a7 08 85 c0 74 16 5b
RSP: 0018:ffffc90000a08bf8 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff9b927a78 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a2a17 RDI: ffffffff8c400c80
RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000002 R14: 0000000000000002 R15: ffff888052e37000
 __debug_check_no_obj_freed lib/debugobjects.c:1180 [inline]
 debug_check_no_obj_freed+0x31f/0x630 lib/debugobjects.c:1201
 __free_pages_prepare mm/page_alloc.c:1413 [inline]
 __free_frozen_pages+0x409/0x1090 mm/page_alloc.c:2950
 __pagetable_free include/linux/mm.h:3695 [inline]
 pagetable_free include/linux/mm.h:3719 [inline]
 pagetable_dtor_free include/linux/mm.h:3818 [inline]
 __tlb_remove_table include/asm-generic/tlb.h:221 [inline]
 __tlb_remove_table_free mm/mmu_gather.c:228 [inline]
 tlb_remove_table_rcu+0x2cf/0x380 mm/mmu_gather.c:291
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897
 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:59 [inline]
RIP: 0010:__unwind_start+0x40d/0x7e0 arch/x86/kernel/unwind_orc.c:785
Code: 00 41 8b 06 85 c0 0f 84 e5 fe ff ff 41 80 7d 00 00 0f 85 9e 02 00 00 41 80 3c 24 00 49 8b 46 08 0f 85 76 02 00 00 49 8b 56 10 <48> 39 c3 72 b3 48 39 d3 73 ae 48 8d 4b 08 48 39 ca 72 a5 48 39 c8
RSP: 0018:ffffc900080df600 EFLAGS: 00000246
RAX: ffffc900080d8000 RBX: ffffc900080df6e0 RCX: ffffc900080e0000
RDX: ffffc900080e0000 RSI: ffff888037a02540 RDI: ffffc900080df600
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900080df650 R11: ffffffff826e9c25 R12: fffff5200101becc
R13: fffff5200101becb R14: ffffc900080df650 R15: ffffc900080df658
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4612 [inline]
 slab_alloc_node mm/slub.c:4945 [inline]
 kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4959
 alloc_empty_file+0x5b/0x1c0 fs/file_table.c:262
 path_openat+0xe7/0x4280 fs/namei.c:4849
 do_file_open+0x20e/0x430 fs/namei.c:4892
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f57e46a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffbde04600 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f57e4e4f880 RCX: 00007f57e46a7407
RDX: 0000000000080000 RSI: 00007fffbde04770 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000557f9bd5e7f5
R13: 0000557f9bd5e7f5 R14: 0000000000000001 R15: 0000557f9bd79140
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g289065 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:27528 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 17704 Comm: syz.1.19146 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc9000655f650 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fd3abd
RDX: ffff88802f4a2540 RSI: ffffffff81fd3a97 RDI: ffff88802f4a2540
RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880
FS:  0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d914ff8 CR3: 0000000054fb4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
 tlb_flush_mmu mm/mmu_gather.c:423 [inline]
 tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549
 exit_mmap+0x454/0xa00 mm/mmap.c:1313
 __mmput+0x12a/0x410 kernel/fork.c:1187
 mmput+0x67/0x80 kernel/fork.c:1210
 exit_mm kernel/exit.c:610 [inline]
 do_exit+0x8b1/0x2ae0 kernel/exit.c:992
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fab03f9de59
Code: Unable to access opcode bytes at 0x7fab03f9de2f.
RSP: 002b:00007fab04e420e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fab04225fa8 RCX: 00007fab03f9de59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fab04225fa8
RBP: 00007fab04225fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab04226038 R14: 00007ffeef693f30 R15: 00007ffeef694018
 </TASK>