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BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:655 [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+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff8880a891dd3f by task syz-executor388/7007

CPU: 1 PID: 7007 Comm: syz-executor388 Not tainted 5.7.0-rc4-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+0x1e9/0x30e lib/dump_stack.c:118
 print_address_description+0x74/0x5c0 mm/kasan/report.c:382
 __kasan_report+0x103/0x1a0 mm/kasan/report.c:511
 kasan_report+0x4d/0x80 mm/kasan/common.c:625

Allocated by task 7007:
 save_stack mm/kasan/common.c:49 [inline]
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc+0x114/0x160 mm/kasan/common.c:495
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x24b/0x330 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2672
 con_font_set drivers/tty/vt/vt.c:4566 [inline]
 con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4631
 vt_ioctl+0x179d/0x3eb0 drivers/tty/vt/vt_ioctl.c:265
 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:771 [inline]
 __do_sys_ioctl fs/ioctl.c:780 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:778
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 6135:
 save_stack mm/kasan/common.c:49 [inline]
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0x125/0x190 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 __do_execve_file+0xc0e/0x1b80 fs/exec.c:1910
 do_execveat_common fs/exec.c:1927 [inline]
 do_execve+0x2f/0x40 fs/exec.c:1944
 call_usermodehelper_exec_async+0x2df/0x480 kernel/umh.c:112
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880a891dc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 319 bytes inside of
 512-byte region [ffff8880a891dc00, ffff8880a891de00)
The buggy address belongs to the page:
page:ffffea0002a24740 refcount:1 mapcount:0 mapping:0000000011613c67 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00025ac3c8 ffffea0002517488 ffff8880aa400a80
raw: 0000000000000000 ffff8880a891d000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a891dc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a891dc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a891dd00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                        ^
 ffff8880a891dd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a891de00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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