================================================================== BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4618 Read of size 2 at addr ffff8880936ee4c0 by task syz-executor.2/27901 CPU: 0 PID: 27901 Comm: syz-executor.2 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] do_splice+0x642/0x12c0 fs/splice.c:1148 __do_sys_splice fs/splice.c:1415 [inline] __se_sys_splice fs/splice.c:1395 [inline] __x64_sys_splice+0x2c6/0x330 fs/splice.c:1395 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:00007f1dd5712c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045a6f9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000100000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1dd57136d4 R13: 00000000004cb1c1 R14: 00000000004e3ad8 R15: 00000000ffffffff Allocated by task 7721: 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_allocate drivers/tty/vt/vt.c:1101 [inline] vc_allocate+0x3f5/0x760 drivers/tty/vt/vt.c:1069 con_install+0x52/0x410 drivers/tty/vt/vt.c:3204 tty_driver_install_tty drivers/tty/tty_io.c:1226 [inline] tty_init_dev drivers/tty/tty_io.c:1339 [inline] tty_init_dev+0xf7/0x460 drivers/tty/tty_io.c:1316 tty_open_by_driver drivers/tty/tty_io.c:1981 [inline] tty_open+0x4bf/0xb70 drivers/tty/tty_io.c:2029 chrdev_open+0x245/0x6b0 fs/char_dev.c:423 do_dentry_open+0x4c3/0x1210 fs/open.c:796 vfs_open+0xa0/0xd0 fs/open.c:905 do_last fs/namei.c:3418 [inline] path_openat+0x10d7/0x45e0 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1088 __do_sys_open fs/open.c:1106 [inline] __se_sys_open fs/open.c:1101 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1101 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 ffff8880936ed200 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 4800 bytes inside of 8192-byte region [ffff8880936ed200, ffff8880936ef200) The buggy address belongs to the page: page:ffffea00024dbb00 count:1 mapcount:0 mapping:ffff88812c315080 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00027d6408 ffffea0002511d08 ffff88812c315080 raw: 0000000000000000 ffff8880936ed200 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880936ee380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880936ee400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880936ee480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff8880936ee500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880936ee580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================