------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/vkms/vkms_crtc.c:21 vkms_vblank_simulate+0x120/0x130 drivers/gpu/drm/vkms/vkms_crtc.c:41
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc2-syzkaller-00338-gf78d76e72a46 #0
Hardware name: linux,dummy-virt (DT)
pstate: 20400089 (nzCv daIf +PAN -UAO -TCO BTYPE=--)
pc : vkms_vblank_simulate+0x120/0x130 drivers/gpu/drm/vkms/vkms_crtc.c:21
lr : hrtimer_forward_now include/linux/hrtimer.h:510 [inline]
lr : vkms_vblank_simulate+0x3c/0x130 drivers/gpu/drm/vkms/vkms_crtc.c:19
sp : ffff800010003e30
x29: ffff800010003e30 x28: ffff00007fbc2e00 
x27: ffff00007fbc2e40 x26: ffff80001096f860 
x25: 0000000000000000 x24: 0000000000000001 
x23: 0000000000000080 x22: 0000000757902c70 
x21: 0000000000fe4c00 x20: f5ff000004e18628 
x19: f5ff000004e19498 x18: 00000000fffffffb 
x17: 000000000000003f x16: 000000000000000a 
x15: 0000000000000020 x14: 00000000000003c8 
x13: 0000000000000000 x12: 0000000000000040 
x11: fbff000004000260 x10: fbff000004000262 
x9 : ffff8000133333f8 x8 : 00000007575b1010 
x7 : 7fffffffffffffff x6 : 00000007575b1010 
x5 : 00000007575b1010 x4 : f5ff000004e19498 
x3 : 0000000758595c10 x2 : 00000007575b1010 
x1 : 0000000758595c10 x0 : 0000000000000002 
Call trace:
 vkms_vblank_simulate+0x120/0x130 drivers/gpu/drm/vkms/vkms_crtc.c:41
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x140/0x1e0 kernel/time/hrtimer.c:1583
 hrtimer_interrupt+0xe8/0x290 kernel/time/hrtimer.c:1645
 timer_handler drivers/clocksource/arm_arch_timer.c:647 [inline]
 arch_timer_handler_phys+0x38/0x50 drivers/clocksource/arm_arch_timer.c:665
 handle_percpu_devid_irq+0x84/0x150 kernel/irq/chip.c:930
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 generic_handle_irq kernel/irq/irqdesc.c:652 [inline]
 __handle_domain_irq+0x7c/0xe0 kernel/irq/irqdesc.c:689
 handle_domain_irq include/linux/irqdesc.h:176 [inline]
 gic_handle_irq+0x50/0xd0 drivers/irqchip/irq-gic.c:370
 el1_irq+0xb4/0x180 arch/arm64/kernel/entry.S:669
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:124 [inline]
 queue_work_on+0x2c/0x80 kernel/workqueue.c:1528
 queue_work include/linux/workqueue.h:507 [inline]
 call_usermodehelper_exec+0x134/0x200 kernel/umh.c:433
 kobject_uevent_env+0x578/0x690 lib/kobject_uevent.c:617
 kobject_uevent+0x14/0x20 lib/kobject_uevent.c:641
 device_add+0x330/0x7d0 drivers/base/core.c:3223
 device_create_groups_vargs+0x108/0x174 drivers/base/core.c:3892
 device_create+0x5c/0x8c drivers/base/core.c:3934
 bdi_register_va+0x80/0x214 mm/backing-dev.c:809
 bdi_register+0x58/0x80 mm/backing-dev.c:841
 __device_add_disk+0x34c/0x4a0 block/genhd.c:618
 device_add_disk+0x14/0x20 block/genhd.c:641
 add_disk include/linux/genhd.h:231 [inline]
 brd_init+0x168/0x214 drivers/block/brd.c:514
 do_one_initcall+0x50/0x1b0 init/main.c:1226
 do_initcall_level init/main.c:1299 [inline]
 do_initcalls init/main.c:1315 [inline]
 do_basic_setup init/main.c:1335 [inline]
 kernel_init_freeable+0x1d8/0x240 init/main.c:1537
 kernel_init+0x14/0x118 init/main.c:1424
 ret_from_fork+0x10/0x34 arch/arm64/kernel/entry.S:958