==================================================================
BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline]
BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: slab-out-of-bounds in bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff8880a1895b35 by task agetty/6521

CPU: 1 PID: 6521 Comm: agetty Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d6/0x29e lib/dump_stack.c:118
 print_address_description+0x66/0x620 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1362
 con_flush drivers/tty/vt/vt.c:2575 [inline]
 do_con_write+0xd42b/0xd580 drivers/tty/vt/vt.c:2916
 con_put_char+0x7d/0xc0 drivers/tty/vt/vt.c:3260
 tty_put_char+0x97/0x110 drivers/tty/tty_io.c:3031
 do_output_char+0x586/0x940 drivers/tty/n_tty.c:488
 __process_echoes+0x2a3/0x930 drivers/tty/n_tty.c:739
 flush_echoes drivers/tty/n_tty.c:829 [inline]
 __receive_buf drivers/tty/n_tty.c:1648 [inline]
 n_tty_receive_buf_common+0x29fa/0x3100 drivers/tty/n_tty.c:1742
 tiocsti drivers/tty/tty_io.c:2196 [inline]
 tty_ioctl+0xd5b/0x15c0 drivers/tty/tty_io.c:2572
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fca046b3017
Code: 00 00 00 48 8b 05 81 7e 2b 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 7e 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007fff1a2b4ad8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fff1a2b4c51 RCX: 00007fca046b3017
RDX: 00007fff1a2b4c50 RSI: 0000000000005412 RDI: 0000000000000000
RBP: 00007fff1a2b4c51 R08: ffffffffffffff98 R09: 00007fff1a2b4b50
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1a2b4af4
R13: 00007fff1a2b4c50 R14: 00007fff1a2b4b50 R15: 0000000000000000

Allocated by task 9832:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x205/0x300 mm/slab.c:3664
 kmalloc include/linux/slab.h:559 [inline]
 fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2694
 con_font_set drivers/tty/vt/vt.c:4663 [inline]
 con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4728
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline]
 vt_ioctl+0xd7f/0x3d70 drivers/tty/vt/vt_ioctl.c:856
 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a1895800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 821 bytes inside of
 1024-byte region [ffff8880a1895800, ffff8880a1895c00)
The buggy address belongs to the page:
page:000000000ca06927 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a1895000 pfn:0xa1895
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027a60c8 ffffea0002446888 ffff8880aa440700
raw: ffff8880a1895000 ffff8880a1895000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a1895a00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a1895a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a1895b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                     ^
 ffff8880a1895b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a1895c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================