================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:399 [inline] BUG: KASAN: slab-out-of-bounds in soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70 Read of size 16 at addr ffff8880971aee10 by task kworker/0:3/2650 CPU: 0 PID: 2650 Comm: kworker/0:3 Not tainted 5.9.0-rc5-next-20200918-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+0x198/0x1fb lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 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:399 [inline] soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0xcfe/0x1720 drivers/video/fbdev/core/bitblit.c:377 fb_flashcursor+0x38b/0x430 drivers/video/fbdev/core/fbcon.c:397 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Allocated by task 28184: 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:3653 [inline] __kmalloc+0x27c/0x4d0 mm/slab.c:3662 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x363/0x9b0 drivers/video/fbdev/core/fbcon.c:2496 con_font_set drivers/tty/vt/vt.c:4667 [inline] con_font_op+0xd26/0x1140 drivers/tty/vt/vt.c:4732 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:594 [inline] vt_ioctl+0x1d94/0x2fb0 drivers/tty/vt/vt_ioctl.c:855 tty_ioctl+0xb24/0x16f0 drivers/tty/tty_io.c:2654 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+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880971aec00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 16 bytes to the right of 512-byte region [ffff8880971aec00, ffff8880971aee00) The buggy address belongs to the page: page:00000000d93ef81a refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880971ae800 pfn:0x971ae flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002527188 ffffea000239c8c8 ffff8880aa040600 raw: ffff8880971ae800 ffff8880971ae000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880971aed00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880971aed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880971aee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880971aee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880971aef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================