rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=7e1/1/0x4000000000000000 softirq=163934/163937 fqs=0 
	(t=10500 jiffies g=214269 q=127)
rcu: rcu_preempt kthread starved for 10500 jiffies! g214269 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:26896 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5162 Comm: syz.3.9849 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__get_user_nocheck_4+0x3/0x10 arch/x86/lib/getuser.S:137
Code: 90 90 90 90 90 90 90 0f 01 cb 0f ae e8 0f b6 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 0f 01 cb <0f> ae e8 8b 10 31 c0 0f 01 ca c3 90 90 0f 01 cb 0f ae e8 48 8b 10
RSP: 0018:ffffc900033ffb18 EFLAGS: 00040202
RAX: 00007f7b2cc02f80 RBX: 0000000000000000 RCX: ffff888020a0bb80
RDX: 0000000000000002 RSI: 0000000000000344 RDI: 0000000000000340
RBP: ffffc900033ffcd0 R08: 0000000000000000 R09: 1ffff9200067ff8b
R10: dffffc0000000000 R11: fffff5200067ff8c R12: dffffc0000000000
R13: 0000000000000344 R14: 00007f7b2cc02f80 R15: 1ffff9200067ff70
FS:  00007f7b2cc036c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54dafb4540 CR3: 00000000222b1000 CR4: 00000000003526e0
Call Trace:
 <TASK>
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:49 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:317 [inline]
 fpu__restore_sig+0x8b3/0x10a0 arch/x86/kernel/fpu/signal.c:466
 restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
 __ia32_sys_rt_sigreturn+0x5ef/0x750 arch/x86/kernel/signal.c:674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7b2e9aae57
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f7b2cc03028 EFLAGS: 00000246
RAX: 0000000000000048 RBX: 00007f7b2ec32fa0 RCX: 00007f7b2e9aae59
RDX: 0000200000000280 RSI: 0000000000000026 RDI: 0000000000000005
RBP: 00007f7b2ea40e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b2ec33038 R14: 00007f7b2ec32fa0 R15: 00007ffea4bc43a8
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 5168 Comm: syz.6.9850 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline]
RIP: 0010:deref_stack_reg+0x76/0x120 arch/x86/kernel/unwind_orc.c:357
Code: e5 88 00 49 8b 6f 10 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 92 00 00 00 41 83 3f 00 0f 95 c0 4d 39 f5 0f 96 c1 20 c1 <4c> 39 f5 0f 97 c0 20 c8 3c 01 75 14 49 8d 46 08 4c 39 e8 0f 97 c1
RSP: 0018:ffffc9000348f4c8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000348f628 RCX: 0000000000000001
RDX: ffffc9000348f628 RSI: ffffc9000348f670 RDI: ffffc9000348f5f8
RBP: ffffc90003490000 R08: ffffc9000348f670 R09: ffffc9000348f638
R10: dffffc0000000000 R11: fffff52000691ec9 R12: dffffc0000000000
R13: ffffc90003488000 R14: ffffc9000348f670 R15: ffffc9000348f5e8
 unwind_next_frame+0x10bb/0x1cf0 arch/x86/kernel/unwind_orc.c:-1
 __unwind_start+0x51a/0x650 arch/x86/kernel/unwind_orc.c:704
 unwind_start arch/x86/include/asm/unwind.h:60 [inline]
 arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 locks_free_lock fs/locks.c:411 [inline]
 posix_lock_inode+0x257d/0x3270 fs/locks.c:1402
 posix_lock_file fs/locks.c:1427 [inline]
 vfs_lock_file fs/locks.c:2400 [inline]
 do_lock_file_wait fs/locks.c:2414 [inline]
 fcntl_setlk+0xa7f/0x1060 fs/locks.c:2492
 do_fcntl+0x533/0x1360 fs/fcntl.c:373
 __do_sys_fcntl fs/fcntl.c:466 [inline]
 __se_sys_fcntl+0xcc/0x190 fs/fcntl.c:451
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f54daf66e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f54d91bf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 00007f54db1eefa0 RCX: 00007f54daf66e59
RDX: 0000200000000280 RSI: 0000000000000026 RDI: 0000000000000003
RBP: 00007f54daffce6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54db1ef038 R14: 00007f54db1eefa0 R15: 00007fffdb6831d8
 </TASK>