public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Philippe Troin <phil@fifi.org>
To: "David S. Miller" <davem@redhat.com>
Cc: linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk
Subject: Re: 2.2.x BUG & PATCH: recvmsg() does not check msg_controllen correctly
Date: 03 Nov 2000 16:17:53 -0800	[thread overview]
Message-ID: <878zr0vbda.fsf@tantale.fifi.org> (raw)
In-Reply-To: <87n1fgvl7a.fsf@tantale.fifi.org> <200011032218.OAA12790@pizda.ninka.net>
In-Reply-To: <200011032218.OAA12790@pizda.ninka.net> ("David S. Miller"'s message of "Fri, 3 Nov 2000 14:18:35 -0800")

"David S. Miller" <davem@redhat.com> writes:

> The real bug is in the setting of MSG_TRUNC (which is the only side
> effect of your change).  So the better fix is:
> 
> --- net/core/scm.c.~1~	Tue Jun 15 09:19:30 1999
> +++ net/core/scm.c	Fri Nov  3 14:18:06 2000
> @@ -251,7 +251,7 @@
>  			msg->msg_controllen -= cmlen;
>  		}
>  	}
> -	if (i < fdnum)
> +	if (i < fdnum || (fdnum && fdmax <= 0))
>  		msg->msg_flags |= MSG_CTRUNC;
>  
>  	/*

Mmmh, no, if fdmax <= 0 (which happens when msg_controllen <
sizeof(struct cmsghdr)), then alls fds are passed, eventually
clobbering past ((char*)(msg_control)+m_controllen).

Run the little test case if you're not convinced...
I stand by my patch :-)

Phil.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

  reply	other threads:[~2000-11-04  0:18 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-11-03 20:45 2.2.x BUG & PATCH: recvmsg() does not check msg_controllen correctly Philippe Troin
2000-11-03 22:18 ` David S. Miller
2000-11-04  0:17   ` Philippe Troin [this message]
2000-11-04  0:38     ` David S. Miller
2000-11-04  3:53       ` Philippe Troin
2000-11-04  4:51         ` David S. Miller
2000-11-05  2:40           ` Philippe Troin
2000-11-06  3:32             ` David S. Miller
2000-11-06  4:07               ` Philippe Troin
2000-11-06  3:57                 ` David S. Miller

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=878zr0vbda.fsf@tantale.fifi.org \
    --to=phil@fifi.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=davem@redhat.com \
    --cc=linux-kernel@vger.kernel.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