BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 190df3067 P4D 190df3067 PUD 1922a9067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 29388 Comm: syz-executor.0 Not tainted 5.4.61-syzkaller-00894-g0ddc717be4a9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881db909cc8 EFLAGS: 00010202
RAX: ffffffff81323f9c RBX: 0000000000000000 RCX: ffff8881cc214d80
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d90bf1c0
RBP: ffff8881d90bf1e0 R08: ffffffff81323e37 R09: ffffed103b7246ef
R10: ffffed103b7246ef R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000101 R14: ffff8881d90bf1c8 R15: ffff8881d90bf1c0
FS:  00007fac8ccd1700(0000) GS:ffff8881db900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000193c94004 CR4: 00000000001606e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x154/0x340 kernel/time/timer.c:1416
 expire_timers+0x35c/0x470 kernel/time/timer.c:1461
 __run_timers+0x602/0x730 kernel/time/timer.c:1792
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1805
 __do_softirq+0x22e/0x569 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x16d/0x180 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x281/0x3f0 arch/x86/kernel/apic/apic.c:1146
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:831
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0xf/0x20 kernel/locking/spinlock.c:199
Code: 30 7c 74 02 58 c3 e8 90 f5 2e fd 58 c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 e8 1b c4 58 fd 66 90 fb 65 ff 0d ed 9f 30 7c <74> 01 c3 e8 69 f5 2e fd c3 0f 1f 84 00 00 00 00 00 e8 fb c3 58 fd
RSP: 0018:ffff8881ce6b78f0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffff888195ad9f38 RCX: ffff8881cc214d80
RDX: 0000000040000002 RSI: 0000000000000000 RDI: ffff8881db931ac0
RBP: ffff8881ce6b7950 R08: ffffffff81568bcd R09: fffffbfff09b2664
R10: fffffbfff09b2664 R11: 0000000000000000 R12: ffff8881db931ac0
R13: ffff8881cc214d80 R14: dffffc0000000000 R15: ffff888195ad9f00
 finish_lock_switch kernel/sched/core.c:3149 [inline]
 finish_task_switch+0x235/0x4c0 kernel/sched/core.c:3249
 context_switch kernel/sched/core.c:3413 [inline]
 __schedule+0x91d/0xec0 kernel/sched/core.c:4109
 schedule+0x126/0x1d0 kernel/sched/core.c:4176
 pipe_wait fs/pipe.c:117 [inline]
 pipe_write+0x9c2/0x1220 fs/pipe.c:497
 call_write_iter include/linux/fs.h:1971 [inline]
 new_sync_write fs/read_write.c:485 [inline]
 __vfs_write+0x579/0x700 fs/read_write.c:498
 vfs_write+0x217/0x4f0 fs/read_write.c:560
 ksys_write+0x168/0x2a0 fs/read_write.c:614
 do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fac8ccd0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000036780 RCX: 000000000045d5b9
RDX: 0000000041395527 RSI: 0000000020000340 RDI: 0000000000000005
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe1e45e0bf R14: 00007fac8ccd19c0 R15: 000000000118cfec
Modules linked in:
CR2: 0000000000000000
---[ end trace 82c978c4484515ab ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881db909cc8 EFLAGS: 00010202
RAX: ffffffff81323f9c RBX: 0000000000000000 RCX: ffff8881cc214d80
RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d90bf1c0
RBP: ffff8881d90bf1e0 R08: ffffffff81323e37 R09: ffffed103b7246ef
R10: ffffed103b7246ef R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000101 R14: ffff8881d90bf1c8 R15: ffff8881d90bf1c0
FS:  00007fac8ccd1700(0000) GS:ffff8881db900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000193c94004 CR4: 00000000001606e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600