bisecting fixing commit since 3e968c9f1401088abc9a19ae6ff571644d37a355
building syzkaller on 676bd07e7e80f8a270af7f0276443c68f4a99e25
testing commit 3e968c9f1401088abc9a19ae6ff571644d37a355 with gcc (GCC) 8.1.0
kernel signature: eac8e4f328d1ea5262afe2bf3f78f11be9f57866849bd3072981e5718fa1859c
run #0: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #1: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #2: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #3: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #4: crashed: KASAN: out-of-bounds Read in ntfs_read_locked_inode
run #5: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #6: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #7: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #8: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
run #9: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
testing current HEAD b3a9e3b9622ae10064826dccb4f7a52bd88c7407
testing commit b3a9e3b9622ae10064826dccb4f7a52bd88c7407 with gcc (GCC) 8.1.0
kernel signature: 5b281107bb2650f94196c9b413d066991fae97ceefc6da31989215c82ab47333
all runs: crashed: KASAN: use-after-free Read in ntfs_read_locked_inode
revisions tested: 2, total time: 17m56.944496402s (build: 10m53.435233701s, test: 6m15.856571753s)
the crash still happens on HEAD
commit msg: Linux 5.8-rc1
crash: KASAN: use-after-free Read in ntfs_read_locked_inode
ntfs: volume version 3.1.
ntfs: (device loop4): map_mft_record_page(): Mft record 0x2 is corrupt.  Run chkdsk.
ntfs: volume version 3.1.
==================================================================
ntfs: volume version 3.1.
BUG: KASAN: use-after-free in ntfs_read_locked_inode+0x43f8/0x5250 fs/ntfs/inode.c:644
Read of size 8 at addr ffff8881b549a2e8 by task syz-executor5/3741

CPU: 0 PID: 3741 Comm: syz-executor5 Not tainted 5.8.0-rc1-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+0x136/0x187 lib/dump_stack.c:118
 print_address_description.constprop.9+0x3f/0x60 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold.12+0x20/0x37 mm/kasan/report.c:530
ntfs: volume version 3.1.
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:156
 ntfs_read_locked_inode+0x43f8/0x5250 fs/ntfs/inode.c:644
 ntfs_iget+0xe6/0x120 fs/ntfs/inode.c:176
 load_and_init_quota fs/ntfs/super.c:1392 [inline]
 load_system_files+0x5b5a/0x6230 fs/ntfs/super.c:2103
 ntfs_fill_super+0x1325/0x2e60 fs/ntfs/super.c:2894
 mount_bdev+0x27b/0x340 fs/super.c:1417
 ntfs_mount+0x10/0x20 fs/ntfs/super.c:3051
 legacy_get_tree+0x103/0x1f0 fs/fs_context.c:592
 vfs_get_tree+0x8b/0x2d0 fs/super.c:1547
 do_new_mount fs/namespace.c:2874 [inline]
 do_mount+0x1293/0x1c40 fs/namespace.c:3199
 __do_sys_mount fs/namespace.c:3409 [inline]
 __se_sys_mount fs/namespace.c:3386 [inline]
 __x64_sys_mount+0x169/0x1c0 fs/namespace.c:3386
 do_syscall_64+0x6e/0xf0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x457e5a
Code: Bad RIP value.
RSP: 002b:00007fc8c1c4fbb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000457e5a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fc8c1c4fc00
RBP: 000000000000005a R08: 0000000020077a00 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 000000000000066c R14: 00000000006fcac0 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006d52680 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1
flags: 0x2fffc0000000000()
ntfs: volume version 3.1.
raw: 02fffc0000000000 ffffea0006d526c8 ffffea0006d52648 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881b549a180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ntfs: volume version 3.1.
 ffff8881b549a200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881b549a280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff8881b549a300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881b549a380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================