vkms_vblank_simulate: vblank timer overrun rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12670/1:b..l rcu: (detected by 0, t=10505 jiffies, g=47233, q=191 ncpus=2) task:syz.0.1857 state:R running task stack:27472 pid:12670 tgid:12665 ppid:5829 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1200 [inline] copy_pmd_range mm/memory.c:1261 [inline] copy_pud_range mm/memory.c:1298 [inline] copy_p4d_range mm/memory.c:1322 [inline] copy_page_range+0x1dee/0x55e0 mm/memory.c:1420 dup_mmap kernel/fork.c:748 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm kernel/fork.c:1752 [inline] copy_process+0x7ccb/0x8c50 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f600318d169 RSP: 002b:00007f6003f48fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f60033a6080 RCX: 00007f600318d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000800400 RBP: 00007f600320e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f60033a6080 R15: 00007fffe2419c88 rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g47233 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=38137 rcu: rcu_preempt kthread starved for 10501 jiffies! g47233 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:27168 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12671 Comm: syz.4.1856 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:64 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:130 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x4d/0x1a0 mm/kasan/generic.c:189 Code: ff ff ff ff ff 7f ff ff 48 39 f8 0f 83 b3 00 00 00 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 <49> c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48 89 da 48 29 RSP: 0018:ffffc90000a28bb8 EFLAGS: 00000806 RAX: dffffc0000000000 RBX: 000000000000006c RCX: ffffffff8195c64e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff96ec6cc8 RBP: 1ffffffff2dd8d99 R08: 0000000000000000 R09: ffffffff96ec6ccf R10: ffffffff96ec6ccf R11: 0000000000000000 R12: 0000000000000002 R13: ffff888035564880 R14: 0000000000000002 R15: ffff888035565370 FS: 00007f42792226c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000001e000 CR3: 000000007cd62000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class+0x4e/0x130 kernel/locking/lockdep.c:230 lookup_chain_cache_add kernel/locking/lockdep.c:3818 [inline] validate_chain kernel/locking/lockdep.c:3874 [inline] __lock_acquire+0x15a9/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1805 [inline] __hrtimer_run_queues+0x2be/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x220/0xcc0 kernel/sched/core.c:5252 Code: a9 0a 00 00 44 8b 0d b3 e6 d9 0e 45 85 c9 0f 85 c0 01 00 00 48 89 df e8 ae f8 ff ff e8 29 f0 38 00 fb 65 48 8b 1d a0 20 7b 7e <48> 8d bb 08 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90004e47710 EFLAGS: 00000206 RAX: 00000000000039a5 RBX: ffff888035564880 RCX: 1ffffffff20c4511 RDX: 0000000000000000 RSI: ffffffff8b6cfc80 RDI: ffffffff8bd36a20 RBP: ffffc90004e47758 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90626c17 R11: 0000000000000000 R12: ffff8880b873fa30 R13: ffff88801d698000 R14: ffff888078d38000 R15: ffff8880b863ec00 context_switch kernel/sched/core.c:5381 [inline] __schedule+0xf4b/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 rdmsr_safe_on_cpu+0x1de/0x210 arch/x86/lib/msr-smp.c:181 msr_read+0x19e/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x1df/0xbf0 fs/read_write.c:563 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f427838d169 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:00007f4279222038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f42785a6080 RCX: 00007f427838d169 RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 000000000000000c RBP: 00007f427840e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f42785a6080 R15: 00007fff9b3236b8