rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=7d1/1/0x4000000000000000 softirq=5817/5817 fqs=0 
	(detected by 0, t=10502 jiffies, g=5109, q=105)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4188 Comm: syz-executor940 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x4b/0x110 lib/smp_processor_id.c:55
Code: 0d 42 78 60 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 74
RSP: 0018:ffffc90000dd0f30 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffff88807978bb80 RCX: 8ab3cc895cccaf00
RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8a59e7a0
RBP: ffffc90000dd0fe0 R08: dffffc0000000000 R09: ffffed1027fd4641
R10: ffffed1027fd4641 R11: 1ffff11027fd4640 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88813fe78018 R15: 1ffff920001ba1e8
FS:  0000555556c0f380(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb20a92130 CR3: 00000000177cd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tick_irq_exit kernel/softirq.c:639 [inline]
 __irq_exit_rcu+0x134/0x220 kernel/softirq.c:661
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x9d/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90002e1f800 EFLAGS: 00000206
RAX: 8ab3cc895cccaf00 RBX: 1ffff920005c3f04 RCX: 8ab3cc895cccaf00
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc90002e1f8e0 R08: dffffc0000000000 R09: ffffed1017227662
R10: ffffed1017227662 R11: 1ffff11017227661 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 pfn_valid include/linux/mmzone.h:-1 [inline]
 __virt_addr_valid+0x3b8/0x470 arch/x86/mm/physaddr.c:65
 free_pages+0x12/0x50 mm/page_alloc.c:5573
 mm_free_pgd kernel/fork.c:653 [inline]
 __mmdrop+0xaa/0x3e0 kernel/fork.c:704
 mmdrop include/linux/sched/mm.h:49 [inline]
 finish_task_switch+0x215/0x640 kernel/sched/core.c:4948
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11c3/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x1f1/0x760 kernel/time/hrtimer.c:2026
 hrtimer_nanosleep+0x2f7/0x520 kernel/time/hrtimer.c:2079
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline]
 __se_sys_clock_nanosleep+0x2e6/0x370 kernel/time/posix-timers.c:1291
 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: 0033:0x7fdb20a3e2c3
Code: 00 00 00 00 00 66 90 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d be 1d 05 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffcb85818d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000001076 RCX: 00007fdb20a3e2c3
RDX: 00007ffcb85818f0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000f4240 R08: 0000000000000044 R09: 0037626ac8d9b868
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000010d44
R13: 00007ffcb858192c R14: 00007ffcb8581940 R15: 00007ffcb8581930
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.026 msecs
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g5109 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=3254
rcu: rcu_preempt kthread starved for 10502 jiffies! g5109 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27880 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 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: 4188 Comm: syz-executor940 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
RIP: 0010:atomic_cmpxchg include/linux/atomic/atomic-instrumented.h:475 [inline]
RIP: 0010:irq_work_single kernel/irq_work.c:162 [inline]
RIP: 0010:irq_work_run_list+0x21c/0x330 kernel/irq_work.c:177
Code: 00 00 00 00 fc ff df 80 3c 08 00 74 05 e8 4c 99 38 00 4c 89 f7 41 ff 56 10 4c 8b 74 24 10 41 83 e7 fc 48 89 df be 04 00 00 00 <e8> cf 9a 38 00 44 89 e8 f0 44 0f b1 3b 4d 85 f6 0f 84 9e 00 00 00
RSP: 0018:ffffc90000dd0f00 EFLAGS: 00000002
RAX: ffff88807978c658 RBX: ffff8880b913b1f8 RCX: ffff88807978bb80
RDX: ffff88807978c658 RSI: 0000000000000004 RDI: ffff8880b913b1f8
RBP: ffffc90000dd0fb0 R08: dffffc0000000000 R09: ffffed1017227640
R10: ffffed1017227640 R11: 1ffff1101722763f R12: 1ffff1100f2f18cb
R13: 0000000000000022 R14: 0000000000000000 R15: 0000000000000020
FS:  0000555556c0f380(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb20a92130 CR3: 00000000177cd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 irq_work_run+0x63/0xe0 kernel/irq_work.c:186
 __sysvec_irq_work+0x98/0x240 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x98/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90002e1f800 EFLAGS: 00000206
RAX: 8ab3cc895cccaf00 RBX: 1ffff920005c3f04 RCX: 8ab3cc895cccaf00
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc90002e1f8e0 R08: dffffc0000000000 R09: ffffed1017227662
R10: ffffed1017227662 R11: 1ffff11017227661 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 pfn_valid include/linux/mmzone.h:-1 [inline]
 __virt_addr_valid+0x3b8/0x470 arch/x86/mm/physaddr.c:65
 free_pages+0x12/0x50 mm/page_alloc.c:5573
 mm_free_pgd kernel/fork.c:653 [inline]
 __mmdrop+0xaa/0x3e0 kernel/fork.c:704
 mmdrop include/linux/sched/mm.h:49 [inline]
 finish_task_switch+0x215/0x640 kernel/sched/core.c:4948
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11c3/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x1f1/0x760 kernel/time/hrtimer.c:2026
 hrtimer_nanosleep+0x2f7/0x520 kernel/time/hrtimer.c:2079
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline]
 __se_sys_clock_nanosleep+0x2e6/0x370 kernel/time/posix-timers.c:1291
 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: 0033:0x7fdb20a3e2c3
Code: 00 00 00 00 00 66 90 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d be 1d 05 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffcb85818d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000001076 RCX: 00007fdb20a3e2c3
RDX: 00007ffcb85818f0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000f4240 R08: 0000000000000044 R09: 0037626ac8d9b868
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000010d44
R13: 00007ffcb858192c R14: 00007ffcb8581940 R15: 00007ffcb8581930
 </TASK>