audit: type=1400 audit(1591462179.748:8): avc:  denied  { execmem } for  pid=6444 comm="syz-executor011" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
==================================================================
BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:674 [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+0xbaa/0xd10 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffffffff87ad55b1 by task syz-executor011/6446

CPU: 0 PID: 6446 Comm: syz-executor011 Not tainted 4.19.126-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x5/0x222 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xbaa/0xd10 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x424/0x4e0 drivers/video/fbdev/core/fbcon.c:1323
 con_flush drivers/tty/vt/vt.c:2552 [inline]
 do_con_write.part.0+0xf37/0x1db0 drivers/tty/vt/vt.c:2802
 do_con_write drivers/tty/vt/vt.c:2571 [inline]
 con_write+0x41/0xe0 drivers/tty/vt/vt.c:3138
 process_output_block drivers/tty/n_tty.c:593 [inline]
 n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331
 do_tty_write drivers/tty/tty_io.c:960 [inline]
 tty_write+0x455/0x790 drivers/tty/tty_io.c:1044
 do_loop_readv_writev fs/read_write.c:704 [inline]
 do_loop_readv_writev fs/read_write.c:688 [inline]
 do_iter_write fs/read_write.c:962 [inline]
 do_iter_write+0x460/0x5e0 fs/read_write.c:941
 vfs_writev+0x15f/0x2f0 fs/read_write.c:1005
 do_writev+0x136/0x330 fs/read_write.c:1040
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4412c9
Code: e8 3c ad 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcf23159b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004412c9
RDX: 0000000000000003 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000009a42 R08: 000000000000000d R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020f0
R13: 0000000000402180 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the variable:
 str__msr__trace_system_name+0x51/0x940

Memory state around the buggy address:
 ffffffff87ad5480: fa fa fa fa 00 00 00 05 fa fa fa fa 00 00 00 00
 ffffffff87ad5500: fa fa fa fa 00 03 fa fa fa fa fa fa 04 fa fa fa
>ffffffff87ad5580: fa fa fa fa 00 00 01 fa fa fa fa fa 00 00 00 02
                                     ^
 ffffffff87ad5600: fa fa fa fa 00 00 00 00 00 fa fa fa fa fa fa fa
 ffffffff87ad5680: 00 00 07 fa fa fa fa fa 00 00 02 fa fa fa fa fa
==================================================================