================================================================== 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 8 at addr ffff88808e07e910 by task syz-executor.1/12039 CPU: 0 PID: 12039 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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 fbcon_cursor+0x537/0x660 drivers/video/fbdev/core/fbcon.c:1411 hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:906 redraw_screen+0x5e3/0x770 drivers/tty/vt/vt.c:1011 vc_do_resize+0xef0/0x1180 drivers/tty/vt/vt.c:1325 vt_resizex drivers/tty/vt/vt_ioctl.c:814 [inline] vt_ioctl+0xeba/0x2c20 drivers/tty/vt/vt_ioctl.c:1026 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+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ce69 Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f88541afc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c340 RCX: 000000000045ce69 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffd4af6083f R14: 00007f88541b09c0 R15: 000000000118bf2c Allocated by task 9689: 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 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:595 [inline] vt_ioctl+0x1be1/0x2c20 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+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88808e07e800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff88808e07e800, ffff88808e07ea00) The buggy address belongs to the page: page:000000004fe4c9e1 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8e07e flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0000854e88 ffffea00024e8ac8 ffff8880aa040600 raw: 0000000000000000 ffff88808e07e000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808e07e800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808e07e880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808e07e900: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808e07e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808e07ea00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================