IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in udf_close_lvid+0x67c/0x770 fs/udf/super.c:2051
Write of size 1 at addr ffff888040dafc18 by task syz-executor.0/8168

CPU: 0 PID: 8168 Comm: syz-executor.0 Not tainted 4.19.211-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+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_store1_noabort+0x88/0x90 mm/kasan/report.c:435
 udf_close_lvid+0x67c/0x770 fs/udf/super.c:2051
 udf_put_super+0x217/0x290 fs/udf/super.c:2361
 generic_shutdown_super+0x144/0x370 fs/super.c:456
 kill_block_super+0x97/0xf0 fs/super.c:1185
 deactivate_locked_super+0x94/0x160 fs/super.c:329
 deactivate_super+0x174/0x1a0 fs/super.c:360
 cleanup_mnt+0x1a8/0x290 fs/namespace.c:1098
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff66b961307
Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffde977bf38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff66b961307
RDX: 00007ffde977c00b RSI: 000000000000000a RDI: 00007ffde977c000
RBP: 00007ffde977c000 R08: 00000000ffffffff R09: 00007ffde977bdd0
R10: 0000555556182903 R11: 0000000000000246 R12: 00007ff66b9b9172
R13: 00007ffde977d0c0 R14: 0000555556182810 R15: 00007ffde977d100

The buggy address belongs to the page:
page:ffffea0001036bc0 count:0 mapcount:-128 mapping:0000000000000000 index:0x1
flags: 0xfff00000000000()
raw: 00fff00000000000 ffffea0001149f08 ffffea0000f49a48 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888040dafb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888040dafb80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888040dafc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff888040dafc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888040dafd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000)
IPVS: ftp: loaded support on port[0] = 21