[syzbot] [ntfs?] kernel BUG in ntfs_truncate

[syzbot] [ntfs?] kernel BUG in ntfs_truncate

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    bff687b3dad6 Merge tag 'block-6.2-2022-12-29' of git://git..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=127fe732480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=68e0be42c8ee4bb4
dashboard link: https://syzkaller.appspot.com/bug?extid=22e381af27f7921a2642
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=175a9dbc480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1542c884480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b1982d688f97/disk-bff687b3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c7c5609f900d/vmlinux-bff687b3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ee4e79832281/bzImage-bff687b3.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ab0785a427df/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+22e381af27f7921a2642@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
ntfs: volume version 3.1.
------------[ cut here ]------------
kernel BUG at fs/ntfs/inode.c:2536!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5076 Comm: syz-executor690 Not tainted 6.2.0-rc1-syzkaller-00068-gbff687b3dad6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:ntfs_truncate+0x269f/0x2720 fs/ntfs/inode.c:2536
Code: 20 80 e1 07 80 c1 03 38 c1 0f 8c c8 f8 ff ff 48 8b 7c 24 20 e8 72 f3 1a ff e9 b9 f8 ff ff e8 98 4b c5 fe 0f 0b e8 91 4b c5 fe <0f> 0b e8 8a 4b c5 fe 0f 0b e8 83 4b c5 fe 0f 0b e8 7c 4b c5 fe 0f
RSP: 0018:ffffc90003c8fae0 EFLAGS: 00010293
RAX: ffffffff82c68fdf RBX: 00000000ffffffe4 RCX: ffff888029970000
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: 0000000000000000
RBP: ffff8880786b7380 R08: ffffffff82c670dd R09: ffffed100f0d6e7b
R10: ffffed100f0d6e7b R11: 1ffff1100f0d6e7a R12: dffffc0000000000
R13: ffff8880786b7380 R14: ffff8880786b7380 R15: 0000000000000000
FS:  0000555556955300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 0000000028ee7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
 ntfs_setattr+0x2b9/0x3a0 fs/ntfs/inode.c:2914
 notify_change+0xe50/0x1100 fs/attr.c:482
 do_truncate+0x200/0x2f0 fs/open.c:65
 vfs_truncate+0x299/0x360 fs/open.c:111
 do_sys_truncate+0xcb/0x180 fs/open.c:134
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f61c4db3769
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc056b7c28 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f61c4db3769
RDX: 00007f61c4d71de3 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007f61c4d73000 R08: 000000000001f1cf R09: 0000000000000000
R10: 00007ffc056b7af0 R11: 0000000000000246 R12: 00007f61c4d73090
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ntfs_truncate+0x269f/0x2720 fs/ntfs/inode.c:2536
Code: 20 80 e1 07 80 c1 03 38 c1 0f 8c c8 f8 ff ff 48 8b 7c 24 20 e8 72 f3 1a ff e9 b9 f8 ff ff e8 98 4b c5 fe 0f 0b e8 91 4b c5 fe <0f> 0b e8 8a 4b c5 fe 0f 0b e8 83 4b c5 fe 0f 0b e8 7c 4b c5 fe 0f
RSP: 0018:ffffc90003c8fae0 EFLAGS: 00010293
RAX: ffffffff82c68fdf RBX: 00000000ffffffe4 RCX: ffff888029970000
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: 0000000000000000
RBP: ffff8880786b7380 R08: ffffffff82c670dd R09: ffffed100f0d6e7b
R10: ffffed100f0d6e7b R11: 1ffff1100f0d6e7a R12: dffffc0000000000
R13: ffff8880786b7380 R14: ffff8880786b7380 R15: 0000000000000000
FS:  0000555556955300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 0000000028ee7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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Re: [syzbot] [ntfs?] kernel BUG in ntfs_truncate

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <jack@suse.cz>
Date:   Wed Nov 1 17:43:10 2023 +0000

    fs: Block writes to mounted block devices

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=179a855fe80000
start commit:   bff687b3dad6 Merge tag 'block-6.2-2022-12-29' of git://git..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=68e0be42c8ee4bb4
dashboard link: https://syzkaller.appspot.com/bug?extid=22e381af27f7921a2642
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=175a9dbc480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1542c884480000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: fs: Block writes to mounted block devices

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [ntfs?] kernel BUG in ntfs_truncate

[Jan Kara]

On Sat 27-01-24 08:12:03, syzbot wrote:
> syzbot suspects this issue was fixed by commit:
> 
> commit 6f861765464f43a71462d52026fbddfc858239a5
> Author: Jan Kara <jack@suse.cz>
> Date:   Wed Nov 1 17:43:10 2023 +0000
> 
>     fs: Block writes to mounted block devices
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=179a855fe80000
> start commit:   bff687b3dad6 Merge tag 'block-6.2-2022-12-29' of git://git..
> git tree:       upstream
> kernel config:  https://syzkaller.appspot.com/x/.config?x=68e0be42c8ee4bb4
> dashboard link: https://syzkaller.appspot.com/bug?extid=22e381af27f7921a2642
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=175a9dbc480000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1542c884480000
> 
> If the result looks correct, please mark the issue as fixed by replying with:

Makes sense:
 
#syz fix: fs: Block writes to mounted block devices

									Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR