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BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:655 [inline]
BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: use-after-free in bit_putcs+0xc08/0xd60 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff8880584680fe by task syz-executor.4/27741

CPU: 1 PID: 27741 Comm: syz-executor.4 Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 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
 do_update_region+0x398/0x630 drivers/tty/vt/vt.c:683
 redraw_screen+0x64c/0x770 drivers/tty/vt/vt.c:1029
 vc_do_resize+0x1007/0x1370 drivers/tty/vt/vt.c:1314
 vt_ioctl+0x200c/0x2640 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:771
 __do_sys_ioctl fs/ioctl.c:780 [inline]
 __se_sys_ioctl fs/ioctl.c:778 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca69
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5ffde10c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f2b40 RCX: 000000000045ca69
RDX: 0000000020000100 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000673 R14: 00000000004c96c1 R15: 00007f5ffde116d4

The buggy address belongs to the page:
page:ffffea0001611a00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0xffff888058468000
flags: 0xfffe0000000000()
raw: 00fffe0000000000 ffffea0000c14608 ffffea0001531e08 0000000000000000
raw: ffff888058468000 0000000000000003 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888058467f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888058468000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888058468080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff888058468100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058468180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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