From: Kees Cook <keescook@chromium.org>
To: NeilBrown <neilb@suse.com>
Cc: Jann Horn <jannh@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-doc@vger.kernel.org,
kernel list <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH mm] VFS: seq_file: ensure ->from is valid.
Date: Mon, 9 Jul 2018 11:16:17 -0700 [thread overview]
Message-ID: <CAGXu5j+F3zUZ6+8cKuurq2fV8L5Piy5dvYrYXeFVG0kVmpZMRw@mail.gmail.com> (raw)
In-Reply-To: <87601ryb8a.fsf@notabene.neil.brown.name>
On Fri, Jul 6, 2018 at 8:29 PM, NeilBrown <neilb@suse.com> wrote:
>
> Previous patch ("VFS: simplify seq_file iteration code and interface")
> removed code to set ->from to zero when ->count is zero, as ->from is
> dead at that time. However it didn't ensure ->from was set properly
> whenever ->count becomes non-zero.
> This can only happen when ->show() is called. Of the three places it
> is called one already has ->from set to zero. The other two are
> fixed by setting from to zero after fully flushing the buffer (at which
> point ->count will also be zero).
>
> Reported-by: Jann Horn <jannh@google.com>
> Signed-off-by: NeilBrown <neilb@suse.com>
I *think* this solves this report, which looks very much like Jann's reproducer:
https://syzkaller.appspot.com/bug?extid=4b712dce5cbce6700f27
-Kees
--
Kees Cook
Pixel Security
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2018-07-09 18:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-15 22:42 [PATCH] VFS: simplify seq_file iteration code and interface NeilBrown
2018-04-30 1:50 ` [PATCH resend] " NeilBrown
2018-04-30 18:03 ` Jonathan Corbet
2018-05-31 22:26 ` [PATCH resend*2] " NeilBrown
2018-06-18 6:46 ` [PATCH resend*3] " NeilBrown
2018-07-07 0:56 ` Jann Horn
2018-07-07 3:23 ` NeilBrown
2018-07-07 3:29 ` [PATCH mm] VFS: seq_file: ensure ->from is valid NeilBrown
2018-07-07 3:50 ` Jann Horn
2018-07-09 18:16 ` Kees Cook [this message]
2018-07-09 19:40 ` Jann Horn
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=CAGXu5j+F3zUZ6+8cKuurq2fV8L5Piy5dvYrYXeFVG0kVmpZMRw@mail.gmail.com \
--to=keescook@chromium.org \
--cc=akpm@linux-foundation.org \
--cc=corbet@lwn.net \
--cc=jannh@google.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=neilb@suse.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/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).