==================================================================
BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4665
Read of size 2 at addr ffff8880a09a0960 by task syz-executor.5/25607

CPU: 1 PID: 25607 Comm: syz-executor.5 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]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:620
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
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:00007f8b31677c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679
RDX: 00000000fffffecb RSI: 0000000020000300 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8b316786d4
R13: 00000000004d3700 R14: 00000000004e52f0 R15: 00000000ffffffff

Allocated by task 10377:
 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_do_resize+0x262/0x1460 drivers/tty/vt/vt.c:1187
 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1304
 fbcon_do_set_font+0x4a6/0x960 drivers/video/fbdev/core/fbcon.c:2599
 fbcon_set_font+0x72e/0x860 drivers/video/fbdev/core/fbcon.c:2696
 con_font_set drivers/tty/vt/vt.c:4538 [inline]
 con_font_op+0xe18/0x1250 drivers/tty/vt/vt.c:4603
 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:244 [inline]
 vt_ioctl+0x35a/0x26d0 drivers/tty/vt/vt_ioctl.c:930
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2658
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:539 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743
 __do_sys_ioctl fs/ioctl.c:750 [inline]
 __se_sys_ioctl fs/ioctl.c:748 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9882:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 kasan_set_free_info mm/kasan/common.c:334 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:473
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:482
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 skb_free_head+0x93/0xb0 net/core/skbuff.c:591
 skb_release_data+0x551/0x8d0 net/core/skbuff.c:611
 skb_release_all+0x4d/0x60 net/core/skbuff.c:665
 __kfree_skb net/core/skbuff.c:679 [inline]
 consume_skb net/core/skbuff.c:838 [inline]
 consume_skb+0xfb/0x410 net/core/skbuff.c:832
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:387 [inline]
 nsim_dev_trap_report_work+0x7cb/0xaf0 drivers/net/netdevsim/dev.c:412
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264
 worker_thread+0x98/0xe40 kernel/workqueue.c:2410
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880a09a0000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2400 bytes inside of
 4096-byte region [ffff8880a09a0000, ffff8880a09a1000)
The buggy address belongs to the page:
page:ffffea0002826800 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0
raw: 00fffe0000010200 ffffea0002442008 ffffea0001544288 ffff8880aa402000
raw: 0000000000000000 ffff8880a09a0000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a09a0800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a09a0880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a09a0900: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                       ^
 ffff8880a09a0980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a09a0a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================