================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline] BUG: KASAN: slab-out-of-bounds in soft_cursor+0x445/0xa40 drivers/video/fbdev/core/softcursor.c:70 Read of size 8 at addr ffff8880a1611dd0 by task syz-executor.2/3497 CPU: 1 PID: 3497 Comm: syz-executor.2 Not tainted 4.14.181-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393 memcpy+0x20/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:347 [inline] soft_cursor+0x445/0xa40 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x1072/0x1660 drivers/video/fbdev/core/bitblit.c:386 fbcon_cursor+0x4b1/0x690 drivers/video/fbdev/core/fbcon.c:1350 hide_cursor+0x7a/0x2a0 drivers/tty/vt/vt.c:590 redraw_screen+0x2a2/0x760 drivers/tty/vt/vt.c:680 vc_do_resize+0xbe0/0xde0 drivers/tty/vt/vt.c:967 vt_ioctl+0x1a64/0x1f20 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45ca29 RSP: 002b:00007f136cb0dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f2b00 RCX: 000000000045ca29 RDX: 00000000200000c0 RSI: 000000000000560a RDI: 0000000000000005 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000673 R14: 00000000004c9681 R15: 00007f136cb0e6d4 Allocated by task 435: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] fbcon_set_font+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2621 con_font_set drivers/tty/vt/vt.c:4182 [inline] con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 17: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcb/0x260 mm/slab.c:3815 __rcu_reclaim kernel/rcu/rcu.h:190 [inline] rcu_do_batch kernel/rcu/tree.c:2699 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline] rcu_process_callbacks+0x89e/0x1180 kernel/rcu/tree.c:2946 __do_softirq+0x254/0x9bf kernel/softirq.c:288 The buggy address belongs to the object at ffff8880a1611cc0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff8880a1611cc0, ffff8880a1611ec0) The buggy address belongs to the page: page:ffffea0002858440 count:1 mapcount:0 mapping:ffff8880a1611040 index:0xffff8880a1611a40 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880a1611040 ffff8880a1611a40 0000000100000004 raw: ffffea00016305e0 ffffea00027be7a0 ffff8880aa800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1611c80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8880a1611d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a1611d80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff8880a1611e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a1611e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================