================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x3fe/0xdb0 drivers/video/fbdev/core/softcursor.c:70 Read of size 9 at addr ffff888094eda930 by task kworker/0:5/8162 CPU: 0 PID: 8162 Comm: kworker/0:5 Not tainted 5.9.0-rc3-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+0x1d6/0x29e 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 16399: 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+0x205/0x300 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2694 con_font_set drivers/tty/vt/vt.c:4663 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4728 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline] vt_ioctl+0xd7f/0x3d70 drivers/tty/vt/vt_ioctl.c:856 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 ffff888094eda800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of 512-byte region [ffff888094eda800, ffff888094edaa00) The buggy address belongs to the page: page:00000000dec00a53 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x94eda flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00029b98c8 ffffea00025fdc48 ffff8880aa440600 raw: 0000000000000000 ffff888094eda000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888094eda800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888094eda880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888094eda900: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888094eda980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888094edaa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================