rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P16588/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=91509, q=203 ncpus=2)
task:syz.5.2634      state:R  running task     stack:24520 pid:16588 tgid:16587 ppid:11032  task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b 13 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90004fced58 EFLAGS: 00000206
RAX: 336549ccfffcc300 RBX: 0000000000000000 RCX: 336549ccfffcc300
RDX: 0000000000000000 RSI: ffffffff8db869c3 RDI: ffffffff8be29d80
RBP: ffffffff8172aae5 R08: 0000000000000000 R09: ffffffff8172aae5
R10: dffffc0000000000 R11: ffffffff81ad00a0 R12: 0000000000000002
R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 folio_alloc_mpol_noprof mm/mempolicy.c:2438 [inline]
 vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2473
 folio_prealloc+0x30/0x180 mm/memory.c:-1
 alloc_anon_folio mm/memory.c:5014 [inline]
 do_anonymous_page mm/memory.c:5071 [inline]
 do_pte_missing mm/memory.c:4249 [inline]
 handle_pte_fault mm/memory.c:6069 [inline]
 __handle_mm_fault+0x2c88/0x5620 mm/memory.c:6212
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6381
 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
RIP: 0010:_inline_copy_to_user include/linux/uaccess.h:197 [inline]
RIP: 0010:_copy_to_user+0x85/0xb0 lib/usercopy.c:26
Code: e8 50 5e fe fc 4d 39 fc 72 3d 4d 39 ec 77 38 e8 e1 5b fe fc 4c 89 f7 89 de e8 67 de 61 fd 0f 01 cb 4c 89 ff 48 89 d9 4c 89 f6 <f3> a4 0f 1f 00 48 89 cb 0f 01 ca 48 89 d8 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc90004fcfb50 EFLAGS: 00050246
RAX: ffffffff84c1d701 RBX: 0000000000001000 RCX: 0000000000000080
RDX: 0000000000000000 RSI: ffff8880294a2f80 RDI: 000020000094d000
RBP: ffffc90004fcfc90 R08: ffff8880294a2fff R09: 1ffff110052945ff
R10: dffffc0000000000 R11: ffffed1005294600 R12: 000020000094d080
R13: 00007ffffffff000 R14: ffff8880294a2000 R15: 000020000094c080
 copy_to_user include/linux/uaccess.h:225 [inline]
 pagemap_read+0x4d4/0x7b0 fs/proc/task_mmu.c:2047
 vfs_read+0x200/0x980 fs/read_write.c:570
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9f74b8e929
RSP: 002b:00007f9f75a71038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f9f74db5fa0 RCX: 00007f9f74b8e929
RDX: 00000000ffffffe2 RSI: 0000200000002080 RDI: 0000000000000004
RBP: 00007f9f74c10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9f74db5fa0 R15: 00007ffc9b9000b8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g91509 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:27072 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 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: 16629 Comm: syz.0.2641 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf6e/0x12d0 kernel/smp.c:885
Code: 89 ee 83 e6 01 31 ff e8 d0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7b 74 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 60 74 0b 00 eb e5 44 89
RSP: 0018:ffffc90004f3fb00 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b863b1c0 RCX: ffff888025cf5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004f3fc58 R08: ffffffff8fa1f5f7 R09: 1ffffffff1f43ebe
R10: dffffc0000000000 R11: fffffbfff1f43ebf R12: 1ffff110170e7f5d
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873fae8
FS:  0000555582ad2500(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003200 CR3: 00000000556f7000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0xfe/0x270 block/bdev.c:712
 blkdev_put_whole block/bdev.c:719 [inline]
 bdev_release+0x417/0x650 block/bdev.c:1144
 blkdev_release+0x15/0x20 block/fops.c:684
 __fput+0x44c/0xa70 fs/file_table.c:465
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a6d98e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3e4e4678 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000ee255 RCX: 00007f1a6d98e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f1a6dbb7ba0 R08: 0000000000000001 R09: 0000000c3e4e496f
R10: 00007f1a6d800000 R11: 0000000000000246 R12: 00007f1a6dbb5fac
R13: 00007f1a6dbb5fa0 R14: ffffffffffffffff R15: 00007ffe3e4e4790
 </TASK>
vkms_vblank_simulate: vblank timer overrun