bisecting fixing commit since c196b3a9c83ae3491280b739d231d02b3cb9d041
building syzkaller on f80ce148aeb891e3335fb38ed9b48b005ca76529
testing commit c196b3a9c83ae3491280b739d231d02b3cb9d041 with gcc (GCC) 8.1.0
kernel signature: 10cd61ee7942f2d304fd45de1caa1f96394aa8c3d6074231f80aa24652cd0d9f
all runs: crashed: KASAN: use-after-free Read in ntfs_iget
testing current HEAD 1752938529c614a8ed4432ecce6ebc95d3b87207
testing commit 1752938529c614a8ed4432ecce6ebc95d3b87207 with gcc (GCC) 8.1.0
kernel signature: 22b9aa3bfe232e8c7195cdae6cb6cb8bb208d3b22d3be49a342c57eaf55ec29d
run #0: crashed: KASAN: use-after-free Read in ntfs_iget
run #1: crashed: KASAN: use-after-free Read in ntfs_iget
run #2: crashed: KASAN: use-after-free Read in ntfs_iget
run #3: crashed: KASAN: out-of-bounds Read in ntfs_iget
run #4: crashed: KASAN: use-after-free Read in ntfs_iget
run #5: crashed: KASAN: use-after-free Read in ntfs_iget
run #6: crashed: KASAN: use-after-free Read in ntfs_iget
run #7: crashed: KASAN: use-after-free Read in ntfs_iget
run #8: crashed: KASAN: use-after-free Read in ntfs_iget
run #9: crashed: KASAN: use-after-free Read in ntfs_iget
revisions tested: 2, total time: 23m25.274514903s (build: 17m6.49136284s, test: 5m32.884035031s)
the crash still happens on HEAD
commit msg: Linux 4.14.213
crash: KASAN: use-after-free Read in ntfs_iget
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
ntfs: (device loop5): ntfs_read_locked_inode(): Failed with error code -2.  Marking corrupt inode 0x1 as bad.  Run chkdsk.
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
ntfs: (device loop5): load_system_files(): Failed to load $MFTMirr.  Mounting read-only.  Run ntfsfix and/or chkdsk.
==================================================================
BUG: KASAN: use-after-free in ntfs_read_locked_inode+0x418b/0x51d0 fs/ntfs/inode.c:677
Read of size 8 at addr ffff888086ec23d5 by task syz-executor.1/9723
ntfs: (device loop0): ntfs_read_locked_inode(): $DATA attribute is missing.

CPU: 0 PID: 9723 Comm: syz-executor.1 Not tainted 4.14.213-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1f1 lib/dump_stack.c:58
 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.7+0x11a/0x2d4 mm/kasan/report.c:409
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 ntfs_read_locked_inode+0x418b/0x51d0 fs/ntfs/inode.c:677
 ntfs_iget+0xda/0x110 fs/ntfs/inode.c:190
 load_and_init_mft_mirror fs/ntfs/super.c:1041 [inline]
 load_system_files fs/ntfs/super.c:1786 [inline]
 ntfs_fill_super+0x13cf/0x76e0 fs/ntfs/super.c:2908
 mount_bdev+0x26f/0x330 fs/super.c:1134
 ntfs_mount+0x10/0x20 fs/ntfs/super.c:3065
 mount_fs+0x7f/0x269 fs/super.c:1237
 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x352/0x2af0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xb1/0xd0 fs/namespace.c:3072
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x460b4a
RSP: 002b:00007fd479fe8a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd479fe8b10 RCX: 0000000000460b4a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd479fe8ad0
RBP: 00007fd479fe8ad0 R08: 00007fd479fe8b10 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 000000002007dc00

The buggy address belongs to the page:
page:ffffea00021bb080 count:1 mapcount:1 mapping:ffff8880a3141699 index:0x556dc3820
flags: 0xfff00000040068(uptodate|lru|active|swapbacked)
raw: 00fff00000040068 ffff8880a3141699 0000000556dc3820 0000000100000000
raw: ffffea00021bb060 ffffea00021bb0e0 0000000000000000 ffff8880b5fd5300
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8880b5fd5300

Memory state around the buggy address:
 ffff888086ec2280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888086ec2300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888086ec2380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffff888086ec2400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888086ec2480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
ntfs: (device loop5): map_mft_record_page(): Mft record 0xa is corrupt.  Run chkdsk.
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!