From: Aleksandr Nogikh <nogikh@google.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: syzbot <syzbot+8edfa01e46fd9fe3fbfb@syzkaller.appspotmail.com>,
akpm@linux-foundation.org, clm@fb.com, dsterba@suse.com,
hch@lst.de, josef@toxicpanda.com, linmiaohe@huawei.com,
linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, torvalds@linux-foundation.org
Subject: Re: [syzbot] WARNING in btrfs_space_info_update_bytes_may_use
Date: Mon, 31 Oct 2022 11:57:00 -0700 [thread overview]
Message-ID: <CANp29Y68VeE9NHM2ekCvuZNVVaEZkmaG_NhyaUTH5DMOu0=QgA@mail.gmail.com> (raw)
In-Reply-To: <Y1/SqIuP4tbszPAW@casper.infradead.org>
On Mon, Oct 31, 2022 at 6:50 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> Dmitry, I don't see a way to tell syzbot that its bisection has gone
> astray. Can you add one or document it if it already exists?
No, unfortunately it's not possible now. I've filed an issue:
https://github.com/google/syzkaller/issues/3491
>
> On Mon, Oct 31, 2022 at 04:51:22AM -0700, syzbot wrote:
> > syzbot has bisected this issue to:
> >
> > commit 0c7c575df56b957390206deb018c41acbb412159
> > Author: Matthew Wilcox (Oracle) <willy@infradead.org>
> > Date: Wed Feb 24 20:01:52 2021 +0000
> >
> > mm/filemap: remove dynamically allocated array from filemap_read
>
> This change affects the read path. The crash happens in the unmount
> path. The data structure that's being checked is modified in the write
> path. I just can't see how this commit is in any way related.
Most likely the bisection pointed at your patch because it removed
kmalloc while the reproducer for the bug does fault injection (see the
"(fail_nth: 10)" line in syz repro). So it might have inadvertently
made the issue more visible to the fuzzer.
>
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=119e21b6880000
> > start commit: b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
> > git tree: upstream
> > final oops: https://syzkaller.appspot.com/x/report.txt?x=139e21b6880000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=159e21b6880000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8edfa01e46fd9fe3fbfb
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17db9ab1880000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=124e21b6880000
> >
> > Reported-by: syzbot+8edfa01e46fd9fe3fbfb@syzkaller.appspotmail.com
> > Fixes: 0c7c575df56b ("mm/filemap: remove dynamically allocated array from filemap_read")
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/Y1/SqIuP4tbszPAW%40casper.infradead.org.
next prev parent reply other threads:[~2022-10-31 18:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-31 0:15 [syzbot] WARNING in btrfs_space_info_update_bytes_may_use syzbot
2022-10-31 11:51 ` syzbot
2022-10-31 13:50 ` Matthew Wilcox
2022-10-31 14:23 ` David Sterba
2022-10-31 18:57 ` Aleksandr Nogikh [this message]
2022-10-31 19:02 ` Aleksandr Nogikh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CANp29Y68VeE9NHM2ekCvuZNVVaEZkmaG_NhyaUTH5DMOu0=QgA@mail.gmail.com' \
--to=nogikh@google.com \
--cc=akpm@linux-foundation.org \
--cc=clm@fb.com \
--cc=dsterba@suse.com \
--cc=hch@lst.de \
--cc=josef@toxicpanda.com \
--cc=linmiaohe@huawei.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=syzbot+8edfa01e46fd9fe3fbfb@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=torvalds@linux-foundation.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).