rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=fea/1/0x4000000000000000 softirq=35596/35597 fqs=4 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
	(detected by 0, t=10502 jiffies, g=49521, q=65)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8399 Comm: syz-executor.0 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:hlock_class kernel/locking/lockdep.c:198 [inline]
RIP: 0010:__lock_acquire+0xb4b/0x54c0 kernel/locking/lockdep.c:4897
Code: 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 f8 06 48 8d 3c c5 a0 a8 a9 8f e8 9d 5c 5e 00 48 0f a3 1d 05 5d 50 0e <0f> 83 0c 0d 00 00 48 8d 1c 5b 48 c1 e3 06 48 81 c3 c0 ac a9 8f 48
RSP: 0018:ffffc90000dc0ad0 EFLAGS: 00000047
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81594b93
RDX: fffffbfff1f53515 RSI: 0000000000000008 RDI: ffffffff8fa9a8a0
RBP: ffff888021b12658 R08: 0000000000000000 R09: ffffffff8fa9a8a7
R10: fffffbfff1f53514 R11: 0000000000000000 R12: ffff888021b11c40
R13: 0000000000000000 R14: ffff888021b12630 R15: 0000000000000000
FS:  000000000206f400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc098cba21 CR3: 0000000067086000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
 debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:656
 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline]
 debug_activate kernel/time/hrtimer.c:475 [inline]
 enqueue_hrtimer+0x27/0x3e0 kernel/time/hrtimer.c:982
 __run_hrtimer kernel/time/hrtimer.c:1554 [inline]
 __hrtimer_run_queues+0xb54/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191
Code: 74 24 10 e8 3a 1b 54 f8 48 89 ef e8 62 d1 54 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 53 9f 48 f8 65 8b 05 fc 69 fc 76 85 c0 74 0a 5b 5d c3 e8 b0 5a
RSP: 0018:ffffc900016dfc38 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1b89de9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888024292720 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8179e0b8 R11: 0000000000000000 R12: ffffc900016dfd20
R13: 00007ffd31bf975c R14: 0000000000000004 R15: 0000000000000000
 do_wait+0x19d/0xa00 kernel/exit.c:1451
 kernel_wait4+0x14c/0x260 kernel/exit.c:1630
 __do_sys_wait4+0x13f/0x150 kernel/exit.c:1658
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4648f7
Code: 89 7c 24 10 48 89 4c 24 18 e8 d5 44 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 05 45 02 00 8b 44
RSP: 002b:00007ffd31bf96c0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000000273 RCX: 00000000004648f7
RDX: 0000000040000001 RSI: 00007ffd31bf975c RDI: 00000000ffffffff
RBP: 00007ffd31bf975c R08: 0000000000000000 R09: 00007ffd31d15090
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 000000000006698b R14: 0000000000000007 R15: 00007ffd31bf97c0
task:syz-executor.4  state:R  running task     stack:27328 pid:17570 ppid:  8407 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4322 [inline]
 __schedule+0x911/0x21b0 kernel/sched/core.c:5073
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5530
 irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x78/0x80 kernel/kcov.c:272
Code: 72 27 41 0f b6 fb 41 0f b6 c9 48 83 c2 01 48 c7 44 30 e0 01 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b <c3> 0f 1f 80 00 00 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48
RSP: 0018:ffffc90001d3f6f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888012f5c980 RCX: ffff888082768000
RDX: 0000000000000000 RSI: ffff888082768000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff87a1ffdf R11: 0000000000000000 R12: 1ffff920003a7ee0
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888012f5c980
 rcu_read_lock include/linux/rcupdate.h:657 [inline]
 sk_psock_get+0x36f/0x400 include/linux/skmsg.h:389
 tls_sw_recvmsg+0x18b/0x16f0 net/tls/tls_sw.c:1760
 inet_recvmsg+0x11b/0x5d0 net/ipv4/af_inet.c:852
 sock_recvmsg_nosec net/socket.c:888 [inline]
 ____sys_recvmsg+0x527/0x600 net/socket.c:2567
 ___sys_recvmsg+0x127/0x200 net/socket.c:2611
 do_recvmmsg+0x24d/0x6d0 net/socket.c:2705
 __sys_recvmmsg net/socket.c:2786 [inline]
 __do_sys_recvmmsg net/socket.c:2807 [inline]
 __se_sys_recvmmsg net/socket.c:2800 [inline]
 __x64_sys_recvmmsg+0x17d/0x260 net/socket.c:2800
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466459
RSP: 002b:00007fdf8c814188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 000000000000161f RSI: 0000000020004bc0 RDI: 0000000000000003
RBP: 00000000004bf9fb R08: 0000000020004dc0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe9c100bff R14: 00007fdf8c814300 R15: 0000000000022000
rcu: rcu_preempt kthread timer wakeup didn't happen for 10493 jiffies! g49521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=22571
rcu: rcu_preempt kthread starved for 10494 jiffies! g49521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29168 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4322 [inline]
 __schedule+0x911/0x21b0 kernel/sched/core.c:5073
 schedule+0xcf/0x270 kernel/sched/core.c:5152
 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892
 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline]
 rcu_gp_kthread+0xd07/0x2250 kernel/rcu/tree.c:2178
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 9649 Comm: kworker/0:5 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events toggle_allocation_gate
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation+0x1c7/0x1e4 kernel/rcu/tree_stall.h:478
 print_other_cpu_stall kernel/rcu/tree_stall.h:582 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq.cold+0x9a3/0x11dd kernel/rcu/tree.c:2650
 update_process_times+0x16d/0x200 kernel/time/timer.c:1796
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:csd_lock_wait kernel/smp.c:228 [inline]
RIP: 0010:smp_call_function_single+0x1b0/0x4b0 kernel/smp.c:516
Code: 10 8b 7c 24 1c 48 8d 74 24 40 48 89 44 24 50 48 8b 44 24 08 48 89 44 24 58 e8 bc fa ff ff 41 89 c5 eb 07 e8 22 42 0b 00 f3 90 <44> 8b 64 24 48 31 ff 41 83 e4 01 44 89 e6 e8 bd 49 0b 00 45 85 e4
RSP: 0018:ffffc900169b7980 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff92002d36f34 RCX: 0000000000000000
RDX: ffff88802dbd3880 RSI: ffffffff8168af4e RDI: 0000000000000003
RBP: ffffc900169b7a58 R08: 0000000000000000 R09: ffffffff8fa9a8a7
R10: ffffffff8168af63 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000008
 smp_call_function_many_cond+0x25f/0x9d0 kernel/smp.c:652
 smp_call_function_many kernel/smp.c:715 [inline]
 smp_call_function kernel/smp.c:737 [inline]
 on_each_cpu+0x4a/0x140 kernel/smp.c:836
 text_poke_sync arch/x86/kernel/alternative.c:1008 [inline]
 text_poke_bp_batch+0x1a7/0x550 arch/x86/kernel/alternative.c:1193
 text_poke_flush arch/x86/kernel/alternative.c:1347 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1344 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1354
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:126
 jump_label_update+0x1da/0x400 kernel/jump_label.c:825
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:609 [inline]
 toggle_allocation_gate+0xbf/0x2e0 mm/kfence/core.c:601
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9649 at drivers/gpu/drm/vkms/vkms_crtc.c:21 vkms_vblank_simulate+0x31e/0x3b0 drivers/gpu/drm/vkms/vkms_crtc.c:21
Modules linked in:
CPU: 0 PID: 9649 Comm: kworker/0:5 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events toggle_allocation_gate
RIP: 0010:vkms_vblank_simulate+0x31e/0x3b0 drivers/gpu/drm/vkms/vkms_crtc.c:21
Code: 85 9e 00 00 00 48 8b 95 b8 01 00 00 4c 89 e1 bf 02 00 00 00 48 c7 c6 80 c5 d8 89 e8 8c 09 f0 ff e9 e5 fe ff ff e8 82 07 27 fd <0f> 0b e9 88 fd ff ff e8 a6 ba 6a fd e9 11 fe ff ff 4c 89 ef e8 99
RSP: 0018:ffffc90000007df0 EFLAGS: 00010046
RAX: 0000000000010003 RBX: ffff888019511e58 RCX: 0000000000000000
RDX: ffff88802dbd3880 RSI: ffffffff844ce9ee RDI: 0000000000000003
RBP: 0000000000000055 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff844ce773 R11: 0000000000000000 R12: ffff888019510d30
R13: 0000000000fe4c00 R14: ffff8880b9c26340 R15: ffffffff844ce6d0
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffdb4d5e00 CR3: 000000000bc8e000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:csd_lock_wait kernel/smp.c:228 [inline]
RIP: 0010:smp_call_function_single+0x1b0/0x4b0 kernel/smp.c:516
Code: 10 8b 7c 24 1c 48 8d 74 24 40 48 89 44 24 50 48 8b 44 24 08 48 89 44 24 58 e8 bc fa ff ff 41 89 c5 eb 07 e8 22 42 0b 00 f3 90 <44> 8b 64 24 48 31 ff 41 83 e4 01 44 89 e6 e8 bd 49 0b 00 45 85 e4
RSP: 0018:ffffc900169b7980 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff92002d36f34 RCX: 0000000000000000
RDX: ffff88802dbd3880 RSI: ffffffff8168af4e RDI: 0000000000000003
RBP: ffffc900169b7a58 R08: 0000000000000000 R09: ffffffff8fa9a8a7
R10: ffffffff8168af63 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000008
 smp_call_function_many_cond+0x25f/0x9d0 kernel/smp.c:652
 smp_call_function_many kernel/smp.c:715 [inline]
 smp_call_function kernel/smp.c:737 [inline]
 on_each_cpu+0x4a/0x140 kernel/smp.c:836
 text_poke_sync arch/x86/kernel/alternative.c:1008 [inline]
 text_poke_bp_batch+0x1a7/0x550 arch/x86/kernel/alternative.c:1193
 text_poke_flush arch/x86/kernel/alternative.c:1347 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1344 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1354
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:126
 jump_label_update+0x1da/0x400 kernel/jump_label.c:825
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:609 [inline]
 toggle_allocation_gate+0xbf/0x2e0 mm/kfence/core.c:601
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294