linux-kernel - Re: NULL Pointer Deference: NFS & Telnet

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20100525.185236.193707791.davem@davemloft.net>
Date:	Tue, 25 May 2010 18:52:36 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	x0066660@...com
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-nfs@...r.kernel.org, linux-omap@...r.kernel.org,
	tony@...mide.com, santosh.shilimkar@...com
Subject: Re: NULL Pointer Deference: NFS & Telnet

From: "Arce, Abraham" <x0066660@...com>
Date: Tue, 25 May 2010 20:48:02 -0500

> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index f8abf68..eb81f76 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -334,7 +334,7 @@ static void skb_release_data(struct sk_buff *skb)
>  	if (!skb->cloned ||
>  	    !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
>  			       &skb_shinfo(skb)->dataref)) {
> -		if (skb_shinfo(skb)->nr_frags) {
> +		if (skb_shinfo(skb)->nr_frags && skb_has_frags(skb)) {
>  			int i;
>  			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
>  				put_page(skb_shinfo(skb)->frags[i].page);

skb_shinfo(skb)->nr_frags counts the number of entries contained
in the skb_shinfo(skb)->frags[] array.

This has nothing to do with the frag list pointer,
skb_shinfo(skb)->frag_list, which is what skb_has_frags()
tests.

You've got some kind of memory corruption going on and it
appears to have nothing to do with the code paths you're
playing with here.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/