rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 2-...!: (1 GPs behind) idle=fda4/1/0x4000000000000000 softirq=126750/126760 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-7): P32136/1:b..l rcu: (detected by 1, t=10506 jiffies, g=164945, q=6997 ncpus=4) Sending NMI from CPU 1 to CPUs 2: NMI backtrace for cpu 2 CPU: 2 UID: 0 PID: 32160 Comm: fido_id Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:native_halt+0x1d/0x30 arch/x86/include/asm/irqflags.h:55 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 17 49 51 00 eb 0c e8 10 49 51 00 0f 00 2d 49 f0 1e 0a e8 04 49 51 00 f4 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 RSP: 0000:ffffc90000538b08 EFLAGS: 00000046 RAX: 0000000000010003 RBX: 0000000000000003 RCX: ffffffff816af0c6 RDX: ffff888024d42480 RSI: ffffffff816b20fc RDI: 0000000000000000 RBP: ffff888024c9c350 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000000003 R13: 0000000000000003 R14: ffff88802b43b400 R15: ffffed100499386a FS: 00007f26e4f99880(0000) GS:ffff888097a12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f26e4aa0000 CR3: 0000000049983000 CR4: 0000000000352ef0 Call Trace: halt arch/x86/include/asm/paravirt.h:112 [inline] kvm_wait+0x147/0x1f0 arch/x86/kernel/kvm.c:1074 pv_wait arch/x86/include/asm/paravirt.h:569 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x4e1/0xcf0 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x20e/0x2b0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162 drm_handle_vblank+0x11b/0xc50 drivers/gpu/drm/drm_vblank.c:1930 vkms_vblank_simulate+0xa8/0x390 drivers/gpu/drm/vkms/vkms_crtc.c:30 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:ptep_get include/linux/pgtable.h:340 [inline] RIP: 0010:__page_table_check_ptes_set+0x132/0x420 mm/page_table_check.c:207 Code: fc ff df 45 85 ed 75 1d eb 74 e8 d9 b7 8c ff 83 c5 01 44 89 ef 48 83 c3 08 89 ee e8 48 b2 8c ff 41 39 ed 74 59 e8 be b7 8c ff <48> 89 d8 48 c1 e8 03 42 80 3c 30 00 0f 85 b3 02 00 00 4c 8b 23 bf RSP: 0000:ffffc900069df918 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff888061ed7570 RCX: ffffffff822fb211 RDX: ffff888024d42480 RSI: ffffffff822fb242 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: dffffc0000000000 R15: 1ffff92000d3bf25 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] set_pte_range+0x4e8/0x740 mm/memory.c:5443 filemap_map_order0_folio mm/filemap.c:3790 [inline] filemap_map_pages+0x59a/0x1b70 mm/filemap.c:3848 do_fault_around mm/memory.c:5656 [inline] do_read_fault mm/memory.c:5689 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing+0xe33/0x3ba0 mm/memory.c:4361 handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6318 handle_mm_fault+0x589/0xd10 mm/memory.c:6487 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f26e50d88e1 Code: 49 39 f2 74 38 48 39 d9 73 33 0f 1f 80 00 00 00 00 48 8b 31 8b 51 08 4c 01 fe 48 83 fa 26 74 0a 48 83 fa 08 0f 85 ef 3c ff ff <48> 8b 51 10 48 83 c1 18 4c 01 fa 48 89 16 48 39 d9 72 d4 4d 8b 9a RSP: 002b:00007ffd2b8fed70 EFLAGS: 00010246 RAX: 00007f26e4a14308 RBX: 00007f26e4ac90c0 RCX: 00007f26e4a9fff0 RDX: 0000000000000008 RSI: 00007f26e4f1a0a0 RDI: 00007f26e4ac9fc0 RBP: 00007ffd2b8fee90 R08: 00007f26e4ac9180 R09: 00007f26e4ac9fc0 R10: 00007f26e50c2580 R11: 0000000000000000 R12: 00007ffd2b8fee20 R13: 00007ffd2b8fee20 R14: 00007f26e50c2580 R15: 00007f26e4a00000 task:syz.0.6953 state:R running task stack:27624 pid:32136 tgid:32133 ppid:23371 task_flags:0x40044c flags:0x10080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113 preempt_schedule_thunk+0x16/0x30 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] zap_pte_range mm/memory.c:1884 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0xf71/0x41b0 mm/memory.c:2017 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:2060 unmap_vmas+0x218/0x470 mm/memory.c:2104 exit_mmap+0x1b2/0xb90 mm/mmap.c:1280 __mmput+0x12a/0x410 kernel/fork.c:1133 mmput+0x62/0x70 kernel/fork.c:1156 exit_mm kernel/exit.c:582 [inline] do_exit+0x7c7/0x2bf0 kernel/exit.c:954 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] __do_fast_syscall_32+0x240/0x300 arch/x86/entry/syscall_32.c:309 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fb7579 RSP: 002b:00000000f548560c EFLAGS: 00000296 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 00000000f7475020 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f7475024 RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10567 jiffies! g164945 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=3 timer-softirq=105659 rcu: rcu_preempt kthread starved for 10568 jiffies! g164945 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=3 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:28696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 3: NMI backtrace for cpu 3 CPU: 3 UID: 0 PID: 32162 Comm: syz.1.6958 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:hrtimer_try_to_cancel+0x42/0x2f0 kernel/time/hrtimer.c:1364 Code: e8 c3 8e 13 00 48 89 df e8 db e1 ff ff 31 ff 89 c5 89 c6 e8 90 89 13 00 40 84 ed 75 1b e8 a6 8e 13 00 44 89 e0 48 83 c4 08 5b <5d> 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 49 be 00 00 00 00 00 fc RSP: 0018:ffffc900068575a0 EFLAGS: 00000082 RAX: 00000000ffffffff RBX: 00000000ffffffff RCX: ffffc90004001000 RDX: 0000000000080000 RSI: ffffffff81a8db5a RDI: 0000000000000001 RBP: ffff88802b427d00 R08: 0000000000000000 R09: ffffed1005684f90 R10: ffff88802b427c83 R11: 0000000000000001 R12: 00000000ffffffff R13: ffff88802b427d00 R14: dffffc0000000000 R15: ffff8880222b5578 FS: 0000000000000000(0000) GS:ffff888097b12000(0063) knlGS:00000000f544db40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000003231cffc CR3: 000000004f8df000 CR4: 0000000000352ef0 Call Trace: hrtimer_cancel+0x16/0x40 kernel/time/hrtimer.c:1481 __disable_vblank drivers/gpu/drm/drm_vblank.c:442 [inline] drm_vblank_disable_and_save+0x283/0x3e0 drivers/gpu/drm/drm_vblank.c:481 drm_crtc_vblank_off+0x31b/0x9b0 drivers/gpu/drm/drm_vblank.c:1364 crtc_disable+0x412/0x640 drivers/gpu/drm/drm_atomic_helper.c:1261 disable_outputs drivers/gpu/drm/drm_atomic_helper.c:1344 [inline] drm_atomic_helper_commit_modeset_disables+0x27/0x60 drivers/gpu/drm/drm_atomic_helper.c:1529 vkms_atomic_commit_tail+0x51/0x240 drivers/gpu/drm/vkms/vkms_drv.c:61 commit_tail+0x28f/0x400 drivers/gpu/drm/drm_atomic_helper.c:1993 drm_atomic_helper_commit+0x2fd/0x380 drivers/gpu/drm/drm_atomic_helper.c:2233 drm_atomic_commit+0x234/0x300 drivers/gpu/drm/drm_atomic.c:1577 drm_atomic_helper_set_config+0x14a/0x1a0 drivers/gpu/drm/drm_atomic_helper.c:3433 drm_mode_setcrtc+0xe21/0x1de0 drivers/gpu/drm/drm_crtc.c:869 drm_ioctl_kernel+0x1f4/0x3e0 drivers/gpu/drm/drm_ioctl.c:797 drm_ioctl+0x5c9/0xc30 drivers/gpu/drm/drm_ioctl.c:894 drm_compat_ioctl+0x327/0x460 drivers/gpu/drm/drm_ioc32.c:379 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf705d579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f544d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000c06864a2 RDX: 00000000800002c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000