From: Greg KH <gregkh@linuxfoundation.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
syzbot <syzbot+16c3a70e1e9b29346c43@syzkaller.appspotmail.com>,
Eric Biggers <ebiggers@google.com>,
Souptick Joarder <jrdr.linux@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
David Rientjes <rientjes@google.com>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: general protection fault in relay_open_buf
Date: Thu, 31 Jan 2019 12:54:01 +0100 [thread overview]
Message-ID: <20190131115401.GA19697@kroah.com> (raw)
In-Reply-To: <f3347711-fc72-a356-0802-4c9c3ce5eb9c@I-love.SAKURA.ne.jp>
On Thu, Jan 31, 2019 at 08:29:37PM +0900, Tetsuo Handa wrote:
> On 2019/01/31 19:51, Greg KH wrote:
> > Can you test the patch below?
>
> You can ask syzbot to test the patch. But
>
> > @@ -461,7 +463,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
> > dentry = chan->cb->create_buf_file(NULL, NULL,
> > S_IRUSR, buf,
> > &chan->is_global);
> > - if (WARN_ON(dentry))
> > + if (IS_ERR_OR_NULL(dentry))
> > goto free_buf;
>
> are you trying to fix a different bug together that old code was by error bailing
> out when chan->cb->create_buf_file() returned a valid "struct dentry *" ?
> I don't know what WARN_ON() due to a valid "struct dentry *" means...
I don't either, I'm guessing that's a code path that has never been
taken, or everyone just ignores it :)
Anyway, I fixed it up to be safe. And the reproducer shows it now works
properly too.
thanks,
greg k-h
next prev parent reply other threads:[~2019-01-31 11:54 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-30 18:53 general protection fault in relay_open_buf syzbot
2019-01-31 9:54 ` Kees Cook
2019-01-31 10:44 ` Greg KH
2019-01-31 10:51 ` Greg KH
2019-01-31 11:16 ` Dmitry Vyukov
2019-01-31 11:22 ` Greg KH
2019-01-31 11:28 ` Dmitry Vyukov
2019-01-31 11:53 ` syzbot
2019-01-31 11:35 ` syzbot
2019-01-31 11:29 ` Tetsuo Handa
2019-01-31 11:54 ` Greg KH [this message]
2019-01-31 18:31 ` Kees Cook
2019-01-31 18:46 ` Greg KH
2019-02-01 3:57 ` Al Viro
2019-02-01 9:07 ` Greg KH
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