================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x3fe/0xdb0 drivers/video/fbdev/core/softcursor.c:70 Read of size 16 at addr ffff88805fd3a7a0 by task kworker/0:4/7577 CPU: 0 PID: 7577 Comm: kworker/0:4 Not tainted 5.8.0-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 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 memcpy+0x25/0x60 mm/kasan/common.c:105 soft_cursor+0x3fe/0xdb0 drivers/video/fbdev/core/softcursor.c:70 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 9887: 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 ffff88805fd3a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1952 bytes inside of 2048-byte region [ffff88805fd3a000, ffff88805fd3a800) The buggy address belongs to the page: page:000000003dc1e37b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fd3a flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a0c0c8 ffffea000231d508 ffff8880aa440800 raw: 0000000000000000 ffff88805fd3a000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805fd3a680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805fd3a700: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805fd3a780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805fd3a800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805fd3a880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================