syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=05cc/1/0x4000000000000000 softirq=17232/17232 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=13665, q=214 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6973 Comm: syz.0.465 Not tainted 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:find_held_lock kernel/locking/lockdep.c:5338 [inline]
RIP: 0010:__lock_release kernel/locking/lockdep.c:5526 [inline]
RIP: 0010:lock_release+0x258/0xa30 kernel/locking/lockdep.c:5872
Code: 84 c0 0f 85 78 05 00 00 8b 06 85 c0 0f 84 2e 02 00 00 48 89 34 24 48 89 54 24 08 48 89 5c 24 28 4c 89 64 24 10 48 89 44 24 38 <8d> 58 ff 4d 8d b5 f0 0a 00 00 4c 63 eb 41 83 fd 31 0f 83 16 06 00
RSP: 0018:ffffc90000007a40 EFLAGS: 00000002
RAX: 0000000000000002 RBX: 0000000000000046 RCX: ffffc90000007a03
RDX: 1ffff92000000f58 RSI: ffff88802feae4e8 RDI: ffffffff8c5fb600
RBP: ffffc90000007b70 R08: ffffffff901a2877 R09: 1ffffffff203450e
R10: dffffc0000000000 R11: fffffbfff203450f R12: 1ffff92000000f54
R13: ffff88802feada00 R14: ffffffff9a5af988 R15: dffffc0000000000
FS:  000055558d8b2500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d8c5588 CR3: 00000000352b4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194
 debug_object_deactivate+0x2d5/0x390 lib/debugobjects.c:888
 debug_hrtimer_deactivate kernel/time/hrtimer.c:460 [inline]
 debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:502
 __run_hrtimer kernel/time/hrtimer.c:1769 [inline]
 __hrtimer_run_queues+0x305/0xd30 kernel/time/hrtimer.c:1865
 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x90 kernel/kcov.c:321
Code: 44 0a 20 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 0c 25 00 d5 03 00 65 8b 05 50 72 44 7e 25 00 01 ff 00 74
RSP: 0018:ffffc9001af37898 EFLAGS: 00000246
RAX: 1ffffd40001a3511 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9001af37978 R08: ffffffff817eebe2 R09: 1ffffffff203450e
R10: dffffc0000000000 R11: fffffbfff203450f R12: 0000000000000018
R13: ffffea0000d1a880 R14: ffffea0000d1a888 R15: ffffc9001af37900
 _compound_head include/linux/page-flags.h:245 [inline]
 mod_lruvec_page_state include/linux/vmstat.h:563 [inline]
 account_kernel_stack+0x142/0x3f0 kernel/fork.c:546
 dup_task_struct+0x2cf/0x8c0 kernel/fork.c:1134
 copy_process+0x5d1/0x3d50 kernel/fork.c:2233
 kernel_clone+0x223/0x870 kernel/fork.c:2815
 __do_sys_clone3 kernel/fork.c:3119 [inline]
 __se_sys_clone3+0x2d8/0x360 kernel/fork.c:3098
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a841c1649
Code: ae 08 00 48 8d 3d dc ae 08 00 e8 e2 28 f6 ff 66 90 b8 ea ff ff ff 48 85 ff 74 2c 48 85 d2 74 27 49 89 c8 b8 b3 01 00 00 0f 05 <48> 85 c0 7c 18 74 01 c3 31 ed 48 83 e4 f0 4c 89 c7 ff d2 48 89 c7
RSP: 002b:00007ffcda285ca8 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f0a84143a30 RCX: 00007f0a841c1649
RDX: 00007f0a84143a30 RSI: 0000000000000058 RDI: 00007ffcda285cf0
RBP: 00007f0a850146c0 R08: 00007f0a850146c0 R09: 00007ffcda285dd7
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000000b R14: 00007ffcda285cf0 R15: 00007ffcda285dd8
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g13665 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:26104 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764
 __schedule_loop kernel/sched/core.c:6841 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6856
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6969 Comm: syz.4.463 Not tainted 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x1ba4/0x2d30 kernel/smp.c:885
Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 b0 e8 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 60 e4 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00
RSP: 0018:ffffc9001bbf7400 EFLAGS: 00000293
RAX: ffffffff81b37985 RBX: 1ffff110170c8c75 RCX: ffff88802f11da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9001bbf7600 R08: ffffffff81b37950 R09: 1ffffffff285870e
R10: dffffc0000000000 R11: fffffbfff285870f R12: ffff8880b873f9c8
R13: ffff8880b86463a8 R14: ffff8880b873f9c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fa1eff8 CR3: 0000000057b5a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:966 [inline]
 flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054
 tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline]
 tlb_flush_mmu+0x1aa/0x680 mm/mmu_gather.c:395
 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488
 exit_mmap+0x52a/0xd40 mm/mmap.c:1297
 __mmput+0x115/0x410 kernel/fork.c:1356
 exit_mm+0x220/0x310 kernel/exit.c:570
 do_exit+0x9ad/0x28e0 kernel/exit.c:925
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x16b2/0x1750 kernel/signal.c:3036
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd80578cde9
Code: Unable to access opcode bytes at 0x7fd80578cdbf.
RSP: 002b:00007fd8066820e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd8059a5fa8 RCX: 00007fd80578cde9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd8059a5fa8
RBP: 00007fd8059a5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd8059a5fac
R13: 0000000000000000 R14: 00007ffc11b23500 R15: 00007ffc11b235e8
 </TASK>
vkms_vblank_simulate: vblank timer overrun