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BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4665
Read of size 2 at addr ffff8880a54e12c0 by task syz-executor128/8917

CPU: 1 PID: 8917 Comm: syz-executor128 Not tainted 5.4.0-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:638
 __asan_report_load2_noabort+0x14/0x20 mm/kasan/generic_report.c:133
 vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4665
 vcs_write+0x646/0xcf0 drivers/tty/vt/vc_screen.c:545
 __vfs_write+0x8a/0x110 fs/read_write.c:494
 vfs_write+0x268/0x5d0 fs/read_write.c:558
 ksys_write+0x14f/0x290 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __ia32_sys_write+0x71/0xb0 fs/read_write.c:620
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f2ba39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000fff02ffc EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020006480
RDX: 0000000000001010 RSI: 00000000080f000c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8898:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:485
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:526
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:561 [inline]
 kzalloc include/linux/slab.h:670 [inline]
 vc_allocate drivers/tty/vt/vt.c:1098 [inline]
 vc_allocate+0x3fc/0x760 drivers/tty/vt/vt.c:1066
 con_install+0x52/0x410 drivers/tty/vt/vt.c:3229
 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline]
 tty_init_dev drivers/tty/tty_io.c:1341 [inline]
 tty_init_dev+0xf7/0x460 drivers/tty/tty_io.c:1318
 tty_open_by_driver drivers/tty/tty_io.c:1985 [inline]
 tty_open+0x4a5/0xbb0 drivers/tty/tty_io.c:2033
 chrdev_open+0x245/0x6b0 fs/char_dev.c:414
 do_dentry_open+0x4e6/0x1380 fs/open.c:797
 vfs_open+0xa0/0xd0 fs/open.c:914
 do_last fs/namei.c:3412 [inline]
 path_openat+0x10e4/0x4710 fs/namei.c:3529
 do_filp_open+0x1a1/0x280 fs/namei.c:3559
 do_sys_open+0x3fe/0x5d0 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1110
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a54e0000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4800 bytes inside of
 8192-byte region [ffff8880a54e0000, ffff8880a54e2000)
The buggy address belongs to the page:
page:ffffea0002953800 refcount:1 mapcount:0 mapping:ffff8880aa4021c0 index:0x0 compound_mapcount: 0
raw: 00fffe0000010200 ffffea0002a6a808 ffffea000252f108 ffff8880aa4021c0
raw: 0000000000000000 ffff8880a54e0000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a54e1180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a54e1200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a54e1280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8880a54e1300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a54e1380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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