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BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [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+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff888063c76470 by task agetty/25070

CPU: 0 PID: 25070 Comm: agetty Not tainted 4.14.202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427
 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x2fe/0x480 drivers/video/fbdev/core/fbcon.c:1247
 con_flush drivers/tty/vt/vt.c:2206 [inline]
 do_con_write+0xaf6/0x19b0 drivers/tty/vt/vt.c:2456
 con_write+0x21/0xa0 drivers/tty/vt/vt.c:2805
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x352/0xda0 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:959 [inline]
 tty_write+0x410/0x740 drivers/tty/tty_io.c:1043
 __vfs_write+0xe4/0x630 fs/read_write.c:480
 vfs_write+0x17f/0x4d0 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xf2/0x210 fs/read_write.c:582
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f2721f68970
RSP: 002b:00007ffce21ebac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f2721f68970
RDX: 0000000000000001 RSI: 00007f2722227683 RDI: 0000000000000001
RBP: 00007f2722227683 R08: 00007f2722228760 R09: 00007f272244a500
R10: 0000000000000230 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000001 R14: 00007f2722227600 R15: 0000000000000001

Allocated by task 23556:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2456
 con_font_set drivers/tty/vt/vt.c:4190 [inline]
 con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4255
 vt_ioctl+0xd91/0x1f50 drivers/tty/vt/vt_ioctl.c:938
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff888063c74e40
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 5680 bytes inside of
 8192-byte region [ffff888063c74e40, ffff888063c76e40)
The buggy address belongs to the page:
page:ffffea00018f1d00 count:1 mapcount:0 mapping:ffff888063c74e40 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff888063c74e40 0000000000000000 0000000100000001
raw: ffffea0001702c20 ffff88813fe81b48 ffff88813fe08080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888063c76300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888063c76380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888063c76400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                             ^
 ffff888063c76480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888063c76500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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