bisecting fixing commit since a1b977b49b66c75e6c51a515f6700371ae720217
building syzkaller on fc7735a27949755327024847e12dcc1b868bcb99
testing commit a1b977b49b66c75e6c51a515f6700371ae720217 with gcc (GCC) 8.1.0
kernel signature: 4c99c28e6543435ca094cc483902be1884308ac3abada3c4124614a32b9d1eb8
all runs: crashed: KASAN: use-after-free Read in ntfs_iget
testing current HEAD 13d2ce42de8cb98ff952f8de6307f896203854c2
testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 with gcc (GCC) 8.1.0
kernel signature: da83cb60ff80d7dadef9b5d830831ed41dcfd736f6f7833ef64ef5ca900d2a98
all runs: crashed: KASAN: use-after-free Read in ntfs_iget
revisions tested: 2, total time: 26m7.532166026s (build: 20m7.723631542s, test: 5m19.273961462s)
the crash still happens on HEAD
commit msg: Linux 4.19.163
crash: KASAN: use-after-free Read in ntfs_iget
ntfs: (device loop0): ntfs_read_locked_inode(): Failed with error code -5.  Marking corrupt inode 0xa as bad.  Run chkdsk.
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
==================================================================
BUG: KASAN: use-after-free in ntfs_read_locked_inode+0x411a/0x51e0 fs/ntfs/inode.c:670
Read of size 8 at addr ffff8881c721a6cd by task syz-executor.1/7402

CPU: 0 PID: 7402 Comm: syz-executor.1 Not tainted 4.19.163-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+0x17c/0x22a lib/dump_stack.c:118
 print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x307 mm/kasan/report.c:412
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:443
 ntfs_read_locked_inode+0x411a/0x51e0 fs/ntfs/inode.c:670
 ntfs_iget+0xe6/0x120 fs/ntfs/inode.c:190
 load_and_init_attrdef fs/ntfs/super.c:1603 [inline]
 load_system_files fs/ntfs/super.c:1831 [inline]
 ntfs_fill_super+0x1ece/0x79d0 fs/ntfs/super.c:2908
 mount_bdev+0x26f/0x330 fs/super.c:1158
 ntfs_mount+0x10/0x20 fs/ntfs/super.c:3065
 mount_fs+0x7f/0x2a2 fs/super.c:1261
 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x376/0x2710 fs/namespace.c:2799
 ksys_mount+0xba/0xe0 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4608aa
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007eff91d0ba88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007eff91d0bb20 RCX: 00000000004608aa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007eff91d0bae0
RBP: 00007eff91d0bae0 R08: 00007eff91d0bb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 000000002007dd00

The buggy address belongs to the page:
page:ffffea00071c8680 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x17ffe0000000000()
raw: 017ffe0000000000 ffffea00071c8688 ffffea00071c8688 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881c721a580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881c721a600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881c721a680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881c721a700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881c721a780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================