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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
Read of size 32 at addr ffff8880965f3c10 by task kworker/1:1/23
CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 5.8.0-rc6-next-20200722-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x1166/0x17d0 drivers/video/fbdev/core/bitblit.c:386
 fb_flashcursor+0x374/0x3e0 drivers/video/fbdev/core/fbcon.c:417
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Allocated by task 12367:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x1a8/0x320 mm/slab.c:3664
 kmalloc include/linux/slab.h:559 [inline]
 fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673
 con_font_set drivers/tty/vt/vt.c:4662 [inline]
 con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4727
 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline]
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:611 [inline]
 vt_ioctl+0x1a9f/0x2c20 drivers/tty/vt/vt_ioctl.c:846
 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8880965f3800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 16 bytes to the right of
 1024-byte region [ffff8880965f3800, ffff8880965f3c00)
The buggy address belongs to the page:
page:000000008ebaaf1a refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x965f3
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002a36808 ffffea00026965c8 ffff8880aa000700
raw: 0000000000000000 ffff8880965f3000 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff8880965f3b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880965f3b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880965f3c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff8880965f3c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880965f3d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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