BUG: unable to handle kernel NULL pointer dereference in fbcon

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	BUG: unable to handle kernel NULL pointer dereference in fbcon_putcs fbdev				2	1040d	1059d	0/26	auto-closed as invalid on 2021/10/24 09:10
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 9fea6067 P4D 9fea6067 PUD 7ad36067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 12095 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000502f6b0 EFLAGS: 00010216
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 000000000000000c
RDX: ffff88801e191000 RSI: ffff888019956000 RDI: ffff8880198cf000
RBP: ffff8880198cf000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff840be042 R11: 0000000000000018 R12: ffff88801e191000
R13: ffff888019956000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fc5419ff700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000078493000 CR4: 00000000003526e0
DR0: 00000000000000fc DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1296
 do_update_region+0x399/0x630 drivers/tty/vt/vt.c:676
 do_con_trol+0xc85/0x54f0 drivers/tty/vt/vt.c:2546
 do_con_write+0xd9d/0x1e40 drivers/tty/vt/vt.c:2951
 con_write+0x21/0x40 drivers/tty/vt/vt.c:3295
 process_output_block drivers/tty/n_tty.c:592 [inline]
 n_tty_write+0x410/0xfd0 drivers/tty/n_tty.c:2288
 do_tty_write drivers/tty/tty_io.c:1038 [inline]
 file_tty_write.constprop.0+0x526/0x910 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write+0x429/0x660 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590
 ksys_write+0x12d/0x250 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc5444aaae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc5419ff188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc5445be020 RCX: 00007fc5444aaae9
RDX: 0000000000001006 RSI: 0000000020001040 RDI: 0000000000000007
RBP: 00007fc544504f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc544af1b2f R14: 00007fc5419ff300 R15: 0000000000022000
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace d37371dca5c844be ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000502f6b0 EFLAGS: 00010216
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 000000000000000c
RDX: ffff88801e191000 RSI: ffff888019956000 RDI: ffff8880198cf000
RBP: ffff8880198cf000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff840be042 R11: 0000000000000018 R12: ffff88801e191000
R13: ffff888019956000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fc5419ff700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000078493000 CR4: 00000000003526e0
DR0: 00000000000000fc DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400