==================================================================
BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:656 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffffffff8896b604 by task agetty/6719
CPU: 0 PID: 6719 Comm: agetty Not tainted 5.8.0-rc4-next-20200713-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 __fb_pad_aligned_buffer include/linux/fb.h:656 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362
 con_flush drivers/tty/vt/vt.c:2568 [inline]
 do_con_write+0xca5/0x1d70 drivers/tty/vt/vt.c:2909
 con_put_char+0x96/0xe0 drivers/tty/vt/vt.c:3253
 tty_put_char+0xb7/0x150 drivers/tty/tty_io.c:3031
 __process_echoes+0x577/0x9f0 drivers/tty/n_tty.c:728
 flush_echoes drivers/tty/n_tty.c:829 [inline]
 __receive_buf drivers/tty/n_tty.c:1648 [inline]
 n_tty_receive_buf_common+0xb88/0x2bc0 drivers/tty/n_tty.c:1742
 tiocsti drivers/tty/tty_io.c:2196 [inline]
 tty_ioctl+0xf2e/0x15f0 drivers/tty/tty_io.c:2572
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f0c67166017
Code: Bad RIP value.
RSP: 002b:00007ffef839cbb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffef839cd34 RCX: 00007f0c67166017
RDX: 00007ffef839cd33 RSI: 0000000000005412 RDI: 0000000000000000
RBP: 00007ffef839cd36 R08: ffffffffffffff98 R09: 00007ffef839cc30
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffef839cbd4
R13: 00007ffef839cd30 R14: 00007ffef839cc30 R15: 0000000000000000
The buggy address belongs to the variable:
 __func__.0+0x104/0x1c0
Memory state around the buggy address:
 ffffffff8896b500: 00 03 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
 ffffffff8896b580: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
>ffffffff8896b600: 04 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
                   ^
 ffffffff8896b680: 07 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
 ffffffff8896b700: 00 04 f9 f9 f9 f9 f9 f9 00 02 f9 f9 f9 f9 f9 f9
==================================================================