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BUG: KASAN: slab-out-of-bounds in soft_cursor+0x62c/0xdb0 drivers/video/fbdev/core/softcursor.c:61
Read of size 1 at addr ffff8880a6f8ed66 by task kworker/0:2/2804

CPU: 0 PID: 2804 Comm: kworker/0:2 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient fb_flashcursor
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1f0/0x31e lib/dump_stack.c:118
 print_address_description+0x66/0x620 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 soft_cursor+0x62c/0xdb0 drivers/video/fbdev/core/softcursor.c:61
 bit_cursor+0x178a/0x2180 drivers/video/fbdev/core/bitblit.c:386
 fb_flashcursor+0x726/0xa10 drivers/video/fbdev/core/fbcon.c:417
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 11592:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x218/0x320 mm/slab.c:3664
 kmalloc include/linux/slab.h:559 [inline]
 fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2673
 con_font_set drivers/tty/vt/vt.c:4662 [inline]
 con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4727
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline]
 vt_ioctl+0xd7f/0x3c60 drivers/tty/vt/vt_ioctl.c:846
 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a6f8ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 358 bytes inside of
 512-byte region [ffff8880a6f8ec00, ffff8880a6f8ee00)
The buggy address belongs to the page:
page:00000000fd34927b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a6f8e800 pfn:0xa6f8e
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00028af848 ffffea000254d088 ffff8880aa440600
raw: ffff8880a6f8e800 ffff8880a6f8e000 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a6f8ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a6f8ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a6f8ed00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff8880a6f8ed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a6f8ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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