netdev - Re: [PATCH] netfilter/IPv6: initialize TOS field in REJECT target module

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: <1303457656.3134.12.camel@edumazet-laptop>
Date:	Fri, 22 Apr 2011 09:34:16 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Fernando Luis Vazquez Cao <fernando@....ntt.co.jp>
Cc:	netfilter-devel@...r.kernel.org, netdev@...r.kernel.org,
	yoshfuji@...ux-ipv6.org, jengelh@...ozas.de, davem@...emloft.net
Subject: Re: [PATCH] netfilter/IPv6:  initialize TOS field in REJECT target
 module

Le vendredi 22 avril 2011 à 16:19 +0900, Fernando Luis Vazquez Cao a
écrit :
> The IPv6 header is not zeroed out in alloc_skb so we must initialize it
> properly unless we want to see IPv6 packets with random TOS fields
> floating around. The current implementation resets the flow label
> but this could be changed if deemed necessary.
> 
> We stumbled upon this issue when trying to apply a mangle rule to
> the RST packet generated by the REJECT target module.
> 
> Signed-off-by: Fernando Luis Vazquez Cao <fernando@....ntt.co.jp>
> ---
> 
> diff -urNp linux-2.6.38.4-orig/net/ipv6/netfilter/ip6t_REJECT.c linux-2.6.38.4/net/ipv6/netfilter/ip6t_REJECT.c
> --- linux-2.6.38.4-orig/net/ipv6/netfilter/ip6t_REJECT.c	2011-03-15 10:20:32.000000000 +0900
> +++ linux-2.6.38.4/net/ipv6/netfilter/ip6t_REJECT.c	2011-04-22 15:00:30.695373543 +0900
> @@ -45,6 +45,8 @@ static void send_reset(struct net *net,
>  	int tcphoff, needs_ack;
>  	const struct ipv6hdr *oip6h = ipv6_hdr(oldskb);
>  	struct ipv6hdr *ip6h;
> +#define DEFAULT_TOS_VALUE	0x0U
> +	const __u8 tclass = DEFAULT_TOS_VALUE;
>  	struct dst_entry *dst = NULL;
>  	u8 proto;
>  	struct flowi fl;
> @@ -123,7 +125,7 @@ static void send_reset(struct net *net,
>  	skb_put(nskb, sizeof(struct ipv6hdr));
>  	skb_reset_network_header(nskb);
>  	ip6h = ipv6_hdr(nskb);
> -	ip6h->version = 6;
> +	*(__be32 *)ip6h =  htonl(0x60000000 | (tclass << 20));

It seems fine but I am wondering where is payload_len set ?



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html