[syzbot] [nilfs2?] kernel BUG in folio_end_writeback

[syzbot] [nilfs2?] kernel BUG in folio_end_writeback

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    0a924817d2ed Merge tag '6.2-rc-smb3-client-fixes-part2' of..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=16228274480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4e2d7bfa2d6d5a76
dashboard link: https://syzkaller.appspot.com/bug?extid=7e5cf1d80677ec185e63
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=14494888480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11c189f8480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b0959a409a79/disk-0a924817.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/388daa76797b/vmlinux-0a924817.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9d2d406c075/bzImage-0a924817.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/166e13821ab4/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7e5cf1d80677ec185e63@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at mm/filemap.c:1615!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.1.0-syzkaller-14321-g0a924817d2ed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:folio_end_writeback+0x34d/0x530 mm/filemap.c:1615
Code: 84 87 00 00 00 e8 13 5a d2 ff e9 36 fd ff ff e8 09 5a d2 ff 4c 89 f7 48 c7 c6 20 84 f8 8a e8 ca 3a 10 00 0f 0b e8 f3 59 d2 ff <0f> 0b e8 ec 59 d2 ff 4c 89 f7 48 c7 c6 60 86 f8 8a e8 ad 3a 10 00
RSP: 0018:ffffc90000147b88 EFLAGS: 00010246
RAX: ffffffff81b9813d RBX: 0000000000000082 RCX: ffff88813fefba80
RDX: 0000000080000100 RSI: ffffffff8aedcc60 RDI: ffffffff8b4bbfe0
RBP: 1ffffd40000ed426 R08: dffffc0000000000 R09: fffffbfff1d2cabe
R10: fffffbfff1d2cabe R11: 1ffffffff1d2cabd R12: ffffea000076a134
R13: dffffc0000000000 R14: ffffea000076a100 R15: 1ffffd40000ed420
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff727105718 CR3: 00000000291ab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 end_bio_bh_io_sync+0xb1/0x110 fs/buffer.c:2655
 req_bio_endio block/blk-mq.c:794 [inline]
 blk_update_request+0x51c/0x1040 block/blk-mq.c:926
 blk_mq_end_request+0x39/0x70 block/blk-mq.c:1053
 blk_complete_reqs block/blk-mq.c:1131 [inline]
 blk_done_softirq+0x119/0x160 block/blk-mq.c:1136
 __do_softirq+0x277/0x738 kernel/softirq.c:571
 run_ksoftirqd+0xa2/0x100 kernel/softirq.c:934
 smpboot_thread_fn+0x533/0xa10 kernel/smpboot.c:164
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_end_writeback+0x34d/0x530 mm/filemap.c:1615
Code: 84 87 00 00 00 e8 13 5a d2 ff e9 36 fd ff ff e8 09 5a d2 ff 4c 89 f7 48 c7 c6 20 84 f8 8a e8 ca 3a 10 00 0f 0b e8 f3 59 d2 ff <0f> 0b e8 ec 59 d2 ff 4c 89 f7 48 c7 c6 60 86 f8 8a e8 ad 3a 10 00
RSP: 0018:ffffc90000147b88 EFLAGS: 00010246
RAX: ffffffff81b9813d RBX: 0000000000000082 RCX: ffff88813fefba80
RDX: 0000000080000100 RSI: ffffffff8aedcc60 RDI: ffffffff8b4bbfe0
RBP: 1ffffd40000ed426 R08: dffffc0000000000 R09: fffffbfff1d2cabe
R10: fffffbfff1d2cabe R11: 1ffffffff1d2cabd R12: ffffea000076a134
R13: dffffc0000000000 R14: ffffea000076a100 R15: 1ffffd40000ed420
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff727105718 CR3: 00000000291ab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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Re: [syzbot] [nilfs?] kernel BUG in folio_end_writeback

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 92c5d1b860e9581d64baca76779576c0ab0d943d
Author: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Date:   Fri May 26 02:13:32 2023 +0000

    nilfs2: reject devices with insufficient block count

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=170c6337a80000
start commit:   929ed21dfdb6 Merge tag '6.4-rc4-smb3-client-fixes' of git:..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=3da6c5d3e0a6c932
dashboard link: https://syzkaller.appspot.com/bug?extid=7e5cf1d80677ec185e63
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16cb3b69280000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10f34201280000

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

#syz fix: nilfs2: reject devices with insufficient block count

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

Re: [syzbot] [nilfs?] kernel BUG in folio_end_writeback

[Ryusuke Konishi]

On Mon, Aug 21, 2023 at 3:41 AM syzbot
<syzbot+7e5cf1d80677ec185e63@syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit 92c5d1b860e9581d64baca76779576c0ab0d943d
> Author: Ryusuke Konishi <konishi.ryusuke@gmail.com>
> Date:   Fri May 26 02:13:32 2023 +0000
>
>     nilfs2: reject devices with insufficient block count
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=170c6337a80000
> start commit:   929ed21dfdb6 Merge tag '6.4-rc4-smb3-client-fixes' of git:..
> git tree:       upstream
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3da6c5d3e0a6c932
> dashboard link: https://syzkaller.appspot.com/bug?extid=7e5cf1d80677ec185e63
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16cb3b69280000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10f34201280000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: nilfs2: reject devices with insufficient block count
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

I have confirmed that one of the five registered reproducers emits the
error message that is output when the above commit takes effect.
However, the remaining four did not.
So, I think it's premature to conclude that the issue has been fixed
by this commit at this time.

Ryusuke Konishi