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BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:655 [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+0xc08/0xd60 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffffffff88962a0b by task syz-executor174/6797

CPU: 0 PID: 6797 Comm: syz-executor174 Not tainted 5.7.0-rc7-next-20200529-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+0x5/0x413 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:655 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xc08/0xd60 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x345/0x3f0 drivers/video/fbdev/core/fbcon.c:1362
 con_flush drivers/tty/vt/vt.c:2574 [inline]
 do_con_write.part.0+0xf16/0x1dc0 drivers/tty/vt/vt.c:2822
 do_con_write drivers/tty/vt/vt.c:2593 [inline]
 con_write+0x41/0xe0 drivers/tty/vt/vt.c:3159
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x3f0/0xf90 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0x495/0x800 drivers/tty/tty_io.c:1046
 do_loop_readv_writev fs/read_write.c:718 [inline]
 do_loop_readv_writev fs/read_write.c:702 [inline]
 do_iter_write fs/read_write.c:1001 [inline]
 do_iter_write+0x486/0x600 fs/read_write.c:980
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1072
 do_writev+0x139/0x300 fs/read_write.c:1115
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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:00007ffd4b273448 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004412c9
RDX: 0000000000000003 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000000d9ef R08: 000000000000000d R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020f0
R13: 0000000000402180 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the variable:
 __func__.46303+0xb/0x1c0

Memory state around the buggy address:
 ffffffff88962900: 00 00 00 00 00 01 fa fa fa fa fa fa 00 00 00 00
 ffffffff88962980: 01 fa fa fa fa fa fa fa 00 00 00 00 fa fa fa fa
>ffffffff88962a00: 00 03 fa fa fa fa fa fa 00 01 fa fa fa fa fa fa
                      ^
 ffffffff88962a80: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
 ffffffff88962b00: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
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