================================================================== BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4618 Read of size 2 at addr ffff888093bf34e0 by task syz-executor.5/14464 CPU: 1 PID: 14464 Comm: syz-executor.5 Not tainted 4.19.88-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:431 vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4618 vcs_write+0x646/0xcf0 drivers/tty/vt/vc_screen.c:526 __vfs_write+0x114/0x810 fs/read_write.c:485 __kernel_write+0x110/0x390 fs/read_write.c:506 write_pipe_buf+0x15d/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x391/0x7d0 fs/splice.c:627 splice_from_pipe+0x108/0x170 fs/splice.c:662 default_file_splice_write+0x3c/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1019 splice_direct_to_actor+0x2e7/0x890 fs/splice.c:974 do_splice_direct+0x1da/0x2a0 fs/splice.c:1062 do_sendfile+0x597/0xce0 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1494 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a6f9 Code: ad 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3227c4ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a6f9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008000fffffffe R11: 0000000000000246 R12: 00007f3227c4f6d4 R13: 00000000004c8fb9 R14: 00000000004e0b38 R15: 00000000ffffffff Allocated by task 8321: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15d/0x750 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] kzalloc include/linux/slab.h:709 [inline] vc_do_resize+0x262/0x14a0 drivers/tty/vt/vt.c:1190 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1307 fbcon_do_set_font+0x4c1/0xa40 drivers/video/fbdev/core/fbcon.c:2577 fbcon_set_font+0x72e/0x860 drivers/video/fbdev/core/fbcon.c:2674 con_font_set drivers/tty/vt/vt.c:4492 [inline] con_font_op+0xe18/0x1250 drivers/tty/vt/vt.c:4557 vt_ioctl+0xd2e/0x2530 drivers/tty/vt/vt_ioctl.c:913 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff888093bf2b80 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 2400 bytes inside of 4096-byte region [ffff888093bf2b80, ffff888093bf3b80) The buggy address belongs to the page: page:ffffea00024efc80 count:1 mapcount:0 mapping:ffff88812c31cdc0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0001730388 ffffea000259f908 ffff88812c31cdc0 raw: 0000000000000000 ffff888093bf2b80 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888093bf3380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888093bf3400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888093bf3480: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ^ ffff888093bf3500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888093bf3580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== kobject: 'kvm' (000000003f55b846): kobject_uevent_env kobject: 'kvm' (000000003f55b846): fill_kobj_path: path = '/devices/virtual/misc/kvm'