------------[ cut here ]------------
WARNING: CPU: 1 PID: 3261 at drivers/gpu/drm/vkms/vkms_crtc.c:21 vkms_vblank_simulate+0x150/0x154 drivers/gpu/drm/vkms/vkms_crtc.c:21
Modules linked in:
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 3261 Comm: syz-fuzzer Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace: 
[<81802550>] (dump_backtrace) from [<818027c4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252)
 r7:00000080 r6:60000193 r5:00000000 r4:82b58344
[<818027ac>] (show_stack) from [<81809e98>] (__dump_stack lib/dump_stack.c:79 [inline])
[<818027ac>] (show_stack) from [<81809e98>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120)
[<81809de0>] (dump_stack) from [<81803358>] (panic+0x130/0x378 kernel/panic.c:231)
 r7:81f48198 r6:82a390a4 r5:00000000 r4:82c6b0d0
[<81803228>] (panic) from [<802446f4>] (__warn+0xb0/0x164 kernel/panic.c:605)
 r3:82a2248c r2:00000000 r1:00000000 r0:81f48198
 r7:00000015
[<80244644>] (__warn) from [<81803608>] (warn_slowpath_fmt+0x68/0xd4 kernel/panic.c:628)
 r7:809fa964 r6:00000015 r5:81fcbd70 r4:00000000
[<818035a4>] (warn_slowpath_fmt) from [<809fa964>] (vkms_vblank_simulate+0x150/0x154 drivers/gpu/drm/vkms/vkms_crtc.c:21)
 r8:00fe4c00 r7:84470720 r6:82a22498 r5:00000000 r4:84471390
[<809fa814>] (vkms_vblank_simulate) from [<80307ebc>] (__run_hrtimer kernel/time/hrtimer.c:1537 [inline])
[<809fa814>] (vkms_vblank_simulate) from [<80307ebc>] (__hrtimer_run_queues+0xd4/0x690 kernel/time/hrtimer.c:1601)
 r9:85878000 r8:ddfdb3e0 r7:ddfdb380 r6:82a22498 r5:00000000 r4:84471390
[<80307de8>] (__hrtimer_run_queues) from [<80308da0>] (hrtimer_interrupt+0x14c/0x2e0 kernel/time/hrtimer.c:1663)
 r10:ddfdb4d8 r9:ddfdb498 r8:ddfdb458 r7:ddfdb4a0 r6:ddfdb4e0 r5:20000193
 r4:ddfdb380
[<80308c54>] (hrtimer_interrupt) from [<8114c308>] (timer_handler drivers/clocksource/arm_arch_timer.c:647 [inline])
[<80308c54>] (hrtimer_interrupt) from [<8114c308>] (arch_timer_handler_virt+0x30/0x38 drivers/clocksource/arm_arch_timer.c:658)
 r10:85879ab8 r9:85879b20 r8:85879a88 r7:8348d940 r6:82a22c34 r5:0000001c
 r4:8348b000
[<8114c2d8>] (arch_timer_handler_virt) from [<802df904>] (handle_percpu_devid_irq+0xa4/0x19c kernel/irq/chip.c:930)
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (generic_handle_irq_desc include/linux/irqdesc.h:158 [inline])
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (generic_handle_irq kernel/irq/irqdesc.c:652 [inline])
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (__handle_domain_irq+0xb0/0x120 kernel/irq/irqdesc.c:689)
 r10:85879ab8 r9:85879b20 r8:00000001 r7:85879df0 r6:828ad498 r5:00000000
 r4:828ad498 r3:00010102
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (handle_domain_irq include/linux/irqdesc.h:176 [inline])
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370)
 r10:ffffffff r9:85878000 r8:e000200c r7:828ad4bc r6:e0002000 r5:85879b20
 r4:82a22c34
[<8088aeec>] (gic_handle_irq) from [<80200abc>] (__irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205)
Exception stack(0x85879b20 to 0x85879b68)
9b20: 00000001 821137b8 00000001 20000193 40000113 ddfdab00 ddfdab00 0005d5e8
9b40: 00000000 82a06d00 ffffffff 85879b84 85879b18 85879b70 8181dacc 81826b50
9b60: 20000113 ffffffff
 r9:85878000 r8:00000000 r7:85879b54 r6:ffffffff r5:20000113 r4:81826b50
[<81826b10>] (_raw_spin_unlock_irqrestore) from [<803066fc>] (__mod_timer+0x2b8/0x424 kernel/time/timer.c:1063)
 r5:ddfdab00 r4:82b643fc
[<80306444>] (__mod_timer) from [<80306894>] (mod_timer+0x14/0x18 kernel/time/timer.c:1106)
 r10:803059dc r9:82a22498 r8:00000101 r7:833af810 r6:00000003 r5:82bfd40c
 r4:82b643fc
[<80306880>] (mod_timer) from [<8097f010>] (isicom_tx+0x88/0x3b0 drivers/tty/isicom.c:500)
[<8097ef88>] (isicom_tx) from [<80305aac>] (call_timer_fn+0xd0/0x570 kernel/time/timer.c:1431)
 r10:803059dc r9:82a22498 r8:00000101 r7:8097ef88 r6:0005d5e7 r5:82bfd40c
 r4:82b643fc
[<803059dc>] (call_timer_fn) from [<80306230>] (expire_timers kernel/time/timer.c:1476 [inline])
[<803059dc>] (call_timer_fn) from [<80306230>] (__run_timers kernel/time/timer.c:1745 [inline])
[<803059dc>] (call_timer_fn) from [<80306230>] (run_timer_softirq+0x2e4/0x384 kernel/time/timer.c:1758)
 r10:0005d5e7 r9:8097ef88 r8:00000000 r7:00000000 r6:ddfdab00 r5:85879c9c
 r4:82b643fc
[<80305f4c>] (run_timer_softirq) from [<802012fc>] (__do_softirq+0x204/0x7ac kernel/softirq.c:345)
 r10:00000002 r9:85878000 r8:82a22498 r7:00000001 r6:00000001 r5:00000002
 r4:82a04084
[<802010f8>] (__do_softirq) from [<8024dff4>] (do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline])
[<802010f8>] (__do_softirq) from [<8024dff4>] (invoke_softirq kernel/softirq.c:228 [inline])
[<802010f8>] (__do_softirq) from [<8024dff4>] (__irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422)
 r10:85879d88 r9:85879df0 r8:00000001 r7:00000000 r6:828ad498 r5:00000000
 r4:828aecc0
[<8024de1c>] (__irq_exit_rcu) from [<8024e1a8>] (irq_exit+0x10/0x3c kernel/softirq.c:446)
 r5:00000000 r4:828ad498
[<8024e198>] (irq_exit) from [<802d8734>] (__handle_domain_irq+0xb4/0x120 kernel/irq/irqdesc.c:692)
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (handle_domain_irq include/linux/irqdesc.h:176 [inline])
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370)
 r10:fffffc3f r9:40000193 r8:e000200c r7:828ad4bc r6:e0002000 r5:85879df0
 r4:82a22c34
[<8088aeec>] (gic_handle_irq) from [<80200abc>] (__irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205)
Exception stack(0x85879df0 to 0x85879e38)
9de0:                                     00000001 821137b8 00000001 20000093
9e00: 20000013 ddfdb380 ddfdb3e0 00000040 ddfdb3e0 82a22928 fffffc3f 85879e54
9e20: 85879de8 85879e40 8181dacc 81826b50 20000013 ffffffff
 r9:85878000 r8:ddfdb3e0 r7:85879e24 r6:ffffffff r5:20000013 r4:81826b50
[<81826b10>] (_raw_spin_unlock_irqrestore) from [<803086ec>] (unlock_hrtimer_base kernel/time/hrtimer.c:915 [inline])
[<81826b10>] (_raw_spin_unlock_irqrestore) from [<803086ec>] (hrtimer_start_range_ns+0x1b4/0x30c kernel/time/hrtimer.c:1153)
 r5:00000001 r4:85879f08
[<80308538>] (hrtimer_start_range_ns) from [<81825ebc>] (hrtimer_start_expires include/linux/hrtimer.h:436 [inline])
[<80308538>] (hrtimer_start_range_ns) from [<81825ebc>] (hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1817 [inline])
[<80308538>] (hrtimer_start_range_ns) from [<81825ebc>] (do_nanosleep+0x84/0x214 kernel/time/hrtimer.c:1893)
 r10:00000000 r9:81825e80 r8:81f47e58 r7:832bba58 r6:85879ea0 r5:85878000
 r4:85879f08
[<81825e38>] (do_nanosleep) from [<803091f0>] (hrtimer_nanosleep+0xf8/0x188 kernel/time/hrtimer.c:1949)
 r9:0000c350 r8:00000000 r7:0000c350 r6:00000001 r5:00000000 r4:0000c350
[<803090f8>] (hrtimer_nanosleep) from [<80309344>] (__do_sys_nanosleep_time32 kernel/time/hrtimer.c:2004 [inline])
[<803090f8>] (hrtimer_nanosleep) from [<80309344>] (sys_nanosleep_time32+0xc4/0x108 kernel/time/hrtimer.c:1991)
 r10:000000a2 r9:85878000 r8:80200224 r7:000000a2 r6:00000000 r5:01c0e008
 r4:00000000
[<80309280>] (sys_nanosleep_time32) from [<80200060>] (ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64)
Exception stack(0x85879fa8 to 0x85879ff0)
9fa0:                   00000000 01c0e008 01c33f74 00000000 00000000 00000014
9fc0: 00000000 01c0e008 00000000 000000a2 00000005 00000000 01c002a0 00002710
9fe0: 0000101c 01c33f70 0007c4b0 0007c4d0
 r4:00000000
Rebooting in 86400 seconds..