netdev - [PATCH] ipv4: fix ip header ident selection in __ip_make

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-next>] [day] [month] [year] [list]

Message-ID: <1345483605.5158.345.camel@edumazet-glaptop>
Date:	Mon, 20 Aug 2012 19:26:45 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	David Miller <davem@...emloft.net>
Cc:	netdev <netdev@...r.kernel.org>,
	Stephen Hemminger <shemminger@...tta.com>,
	Christian Casteyde <casteyde.christian@...e.fr>
Subject: [PATCH] ipv4: fix ip header ident selection in __ip_make_skb()

From: Eric Dumazet <edumazet@...gle.com>

Christian Casteyde reported a kmemcheck 32-bit read from uninitialized
memory in __ip_select_ident().

It turns out that __ip_make_skb() called ip_select_ident() before
properly initializing iph->daddr.

This is a bug uncovered by commit 1d861aa4b3fb (inet: Minimize use of
cached route inetpeer.)

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=46131

Reported-by: Christian Casteyde <casteyde.christian@...e.fr>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Stephen Hemminger <shemminger@...tta.com>
---
 net/ipv4/ip_output.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 147ccc3..c196d74 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1338,10 +1338,10 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 	iph->ihl = 5;
 	iph->tos = inet->tos;
 	iph->frag_off = df;
-	ip_select_ident(iph, &rt->dst, sk);
 	iph->ttl = ttl;
 	iph->protocol = sk->sk_protocol;
 	ip_copy_addrs(iph, fl4);
+	ip_select_ident(iph, &rt->dst, sk);
 
 	if (opt) {
 		iph->ihl += opt->optlen>>2;


--
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