rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=6b94/1/0x4000000000000000 softirq=23916/23916 fqs=0
	(detected by 0, t=10502 jiffies, g=27825, q=89 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7214 Comm: syz.4.1064 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_acquire+0x1f6/0x490 kernel/locking/lockdep.c:5665
Code: 05 df 8d 9f 7e 83 f8 01 0f 85 f9 00 00 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 <0f> 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e
RSP: 0018:ffffc900001e0ae0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 8614eeeacdb26200
RDX: 0000000000000000 RSI: ffffffff8a6c1160 RDI: ffffffff8abf1360
RBP: ffffc900001e0be8 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 0000000000000001
R13: 1ffff9200003c168 R14: 0000000000000046 R15: dffffc0000000000
FS:  00007f71e0d476c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f99f27000 CR3: 000000007ccfe000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x6a/0x490 lib/debugobjects.c:698
 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline]
 debug_activate kernel/time/hrtimer.c:503 [inline]
 enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1110
 __run_hrtimer kernel/time/hrtimer.c:1769 [inline]
 __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1816
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 de d0 49 f7 48 89 df e8 36 96 4a f7 e8 31 97 6d f7 fb bf 01 00 00 00 <e8> 46 13 3e f7 65 8b 05 17 d4 e8 75 85 c0 74 02 5b c3 e8 64 e5 e6
RSP: 0018:ffffc900055277b0 EFLAGS: 00000282
RAX: 8614eeeacdb26200 RBX: ffff88807ae4eec0 RCX: 8614eeeacdb26200
RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001
RBP: ffffc90005527940 R08: dffffc0000000000 R09: fffffbfff211705d
R10: fffffbfff211705d R11: 1ffffffff211705c R12: 0000000000000cc0
R13: 00000003fffffffc R14: ffffc90005527880 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 shmem_add_to_page_cache+0xa5e/0x1c00 mm/shmem.c:740
 shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
 shmem_get_folio mm/shmem.c:2072 [inline]
 shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
 generic_perform_write+0x2db/0x560 mm/filemap.c:3846
 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974
 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x44c/0x960 fs/read_write.c:584
 ksys_write+0x143/0x240 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f71dff8d3df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f71e0d46df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f71dff8d3df
RDX: 0000000001000000 RSI: 00007f71d57f7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000004446
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f71e0d46ef0 R14: 00007f71e0d46eb0 R15: 00007f71d57f7000
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g27825 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=10201
rcu: rcu_preempt kthread starved for 10502 jiffies! g27825 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:27848 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 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: 7214 Comm: syz.4.1064 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:mark_usage kernel/locking/lockdep.c:4549 [inline]
RIP: 0010:__lock_acquire+0xd6f/0x7c50 kernel/locking/lockdep.c:5003
Code: 00 00 00 e8 d3 a5 00 00 49 b8 00 00 00 00 00 fc ff df 85 c0 0f 84 85 4c 00 00 4c 89 e7 4c 89 f6 ba 08 00 00 00 e8 b1 a5 00 00 <85> c0 0f 84 5b 4c 00 00 48 c7 c0 20 f1 9b 96 48 c1 e8 03 49 b8 00
RSP: 0018:ffffc900001e08e0 EFLAGS: 00000082
RAX: 0000000000000001 RBX: ffff88802fb8e404 RCX: ffffffff8163a354
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff908b8248
RBP: ffffc900001e0b30 R08: dffffc0000000000 R09: fffffbfff211704a
R10: fffffbfff211704a R11: 1ffffffff2117049 R12: ffff88802fb8d940
R13: ffff88802fb8e402 R14: ffff88802fb8e470 R15: ffff88802fb8e490
FS:  00007f71e0d476c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f99f27000 CR3: 000000007ccfe000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1756 [inline]
 __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1816
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 de d0 49 f7 48 89 df e8 36 96 4a f7 e8 31 97 6d f7 fb bf 01 00 00 00 <e8> 46 13 3e f7 65 8b 05 17 d4 e8 75 85 c0 74 02 5b c3 e8 64 e5 e6
RSP: 0018:ffffc900055277b0 EFLAGS: 00000282
RAX: 8614eeeacdb26200 RBX: ffff88807ae4eec0 RCX: 8614eeeacdb26200
RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001
RBP: ffffc90005527940 R08: dffffc0000000000 R09: fffffbfff211705d
R10: fffffbfff211705d R11: 1ffffffff211705c R12: 0000000000000cc0
R13: 00000003fffffffc R14: ffffc90005527880 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 shmem_add_to_page_cache+0xa5e/0x1c00 mm/shmem.c:740
 shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
 shmem_get_folio mm/shmem.c:2072 [inline]
 shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
 generic_perform_write+0x2db/0x560 mm/filemap.c:3846
 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974
 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x44c/0x960 fs/read_write.c:584
 ksys_write+0x143/0x240 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f71dff8d3df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f71e0d46df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f71dff8d3df
RDX: 0000000001000000 RSI: 00007f71d57f7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000004446
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f71e0d46ef0 R14: 00007f71e0d46eb0 R15: 00007f71d57f7000
 </TASK>