rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4935/1:b..l
	(detected by 0, t=10502 jiffies, g=15561, q=87 ncpus=2)
task:syz.2.143       state:R  running task     stack:22864 pid:4935  ppid:4276   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6732
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6756
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xf0f/0x11e0 mm/filemap.c:3531
 do_fault_around mm/memory.c:4598 [inline]
 do_read_fault mm/memory.c:4624 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x25e5/0x3d40 mm/memory.c:5292
 faultin_page mm/gup.c:1026 [inline]
 __get_user_pages+0x40d/0xec0 mm/gup.c:1250
 __get_user_pages_locked mm/gup.c:1454 [inline]
 get_dump_page+0x18c/0x670 mm/gup.c:1952
 dump_user_range+0x123/0x840 fs/coredump.c:975
 elf_core_dump+0x30ca/0x3630 fs/binfmt_elf.c:2354
 do_coredump+0x16c1/0x2480 fs/coredump.c:824
 get_signal+0x1093/0x1340 kernel/signal.c:2870
 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:319
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1485
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f78c1b9e161
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f78c1e26090 RCX: 00007f78c1b9e159
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f78c1c3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f78c1e26128 R14: 00007f78c1e26090 R15: 00007fffba83ee68
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10262 jiffies! g15561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=7519
rcu: rcu_preempt kthread starved for 10268 jiffies! g15561 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:27920 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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: 4980 Comm: syz.1.154 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:irq_exit_rcu+0x0/0x20 kernel/softirq.c:691
Code: 89 d9 80 e1 07 80 c1 03 38 c1 7c 81 48 89 df e8 c6 2e 84 00 e9 74 ff ff ff 90 e8 db 50 e3 08 e9 16 ff ff ff 66 0f 1f 44 00 00 <e8> 1b 00 00 00 48 c7 c7 c0 0e 8b 8a e8 bf 54 e3 08 65 ff 0d 0c 2d
RSP: 0018:ffffc900001e0ff0 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffffc900032378b8 RCX: b122326bd85cdc00
RDX: 0000000000000000 RSI: ffffffff8a88f840 RDI: ffffffff8adf68a0
RBP: 0000000000000000 R08: ffffffff8e20b46f R09: 1ffffffff1c4168d
R10: dffffc0000000000 R11: fffffbfff1c4168e R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f57494f66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30014ff8 CR3: 0000000079df2000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5682
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90003237960 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: b122326bd85cdc00
RDX: 0000000000000000 RSI: ffffffff8a8c2a20 RDI: ffffffff8adf68a0
RBP: ffffc90003237a70 R08: dffffc0000000000 R09: 1ffffffff2161e4e
R10: dffffc0000000000 R11: fffffbfff2161e4f R12: 0000000000000001
R13: 1ffff92000646f38 R14: 0000000000000246 R15: dffffc0000000000
 __might_fault+0xc2/0x120 mm/memory.c:5850
 __copy_to_user include/linux/uaccess.h:111 [inline]
 save_xstate_epilog arch/x86/kernel/fpu/signal.c:127 [inline]
 copy_fpstate_to_sigframe+0xaa9/0xd70 arch/x86/kernel/fpu/signal.c:245
 get_sigframe arch/x86/kernel/signal.c:297 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:472 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
 handle_signal arch/x86/kernel/signal.c:828 [inline]
 arch_do_signal_or_restart+0x67a/0x1310 arch/x86/kernel/signal.c:873
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 __syscall_exit_to_user_mode_work kernel/entry/common.c:295 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:306
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f574859e157
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:00007f57494f6028 EFLAGS: 00000246
RAX: 0000000000000028 RBX: 00007f5748826090 RCX: 00007f574859e159
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006
RBP: 00007f574863506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000020000023896 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5748826128 R14: 00007f5748826090 R15: 00007ffc171ce628
 </TASK>