================================================================== 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 3 at addr ffff888088a919a5 by task syz-executor.2/14310 CPU: 1 PID: 14310 Comm: syz-executor.2 Not tainted 4.14.177-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+0x13e/0x194 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1e2 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+0xa9/0x2ae 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+0x10d9/0x1700 drivers/video/fbdev/core/bitblit.c:386 fbcon_cursor+0x4be/0x690 drivers/video/fbdev/core/fbcon.c:1350 hide_cursor+0x7a/0x2a0 drivers/tty/vt/vt.c:590 redraw_screen+0x2a1/0x770 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+0x6c5/0x1220 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+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007fd8ae893c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f2640 RCX: 000000000045c829 RDX: 00000000200000c0 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000066c R14: 00000000004c9401 R15: 00007fd8ae8946d4 Allocated by task 18744: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7c0 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+0x6c5/0x1220 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+0x42/0xb7 Freed by task 1: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcb/0x260 mm/slab.c:3815 kernfs_fop_release+0x10d/0x180 fs/kernfs/file.c:783 __fput+0x25f/0x790 fs/file_table.c:210 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff888088a91800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 421 bytes inside of 512-byte region [ffff888088a91800, ffff888088a91a00) The buggy address belongs to the page: page:ffffea000222a440 count:1 mapcount:0 mapping:ffff888088a91080 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff888088a91080 0000000000000000 0000000100000006 raw: ffffea0001599f60 ffffea00027265a0 ffff88812fe54940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888088a91880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888088a91900: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888088a91980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888088a91a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888088a91a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================