==================================================================
BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:95 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs+0xa63/0xde0 drivers/video/fbdev/core/bitblit.c:184
Read of size 1 at addr ffffffff8c186cc5 by task syz.0.2833/16164

CPU: 3 UID: 0 PID: 16164 Comm: syz.0.2833 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:95 [inline]
 bit_putcs+0xa63/0xde0 drivers/video/fbdev/core/bitblit.c:184
 fbcon_putcs+0x380/0x4a0 drivers/video/fbdev/core/fbcon.c:1314
 con_putc+0x141/0x170 drivers/tty/vt/vt.c:301
 add_softcursor+0x252/0x290 drivers/tty/vt/vt.c:835
 set_cursor drivers/tty/vt/vt.c:865 [inline]
 set_cursor+0x136/0x250 drivers/tty/vt/vt.c:858
 con_flush_chars drivers/tty/vt/vt.c:3586 [inline]
 con_write+0x89/0xb0 drivers/tty/vt/vt.c:3517
 process_output_block drivers/tty/n_tty.c:561 [inline]
 n_tty_write+0x412/0x1160 drivers/tty/n_tty.c:2377
 iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
 file_tty_write.constprop.0+0x501/0x9b0 drivers/tty/tty_io.c:1081
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6c4/0x1150 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf705e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f502d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000080002080
RDX: 0000000000001006 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The buggy address belongs to the variable:
 type_check_kinds+0x785/0xc80

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xc186
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea0000306188 ffffea0000306188 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff8c186b80: 00 00 00 02 f9 f9 f9 f9 00 00 01 f9 f9 f9 f9 f9
 ffffffff8c186c00: 00 00 00 02 f9 f9 f9 f9 05 f9 f9 f9 f9 f9 f9 f9
>ffffffff8c186c80: 05 f9 f9 f9 f9 f9 f9 f9 05 f9 f9 f9 f9 f9 f9 f9
                                           ^
 ffffffff8c186d00: 05 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 06 f9 f9 f9
 ffffffff8c186d80: f9 f9 f9 f9 00 00 00 00 00 00 01 f9 f9 f9 f9 f9
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi