netdev - Re: regression when connecting to ipv6 localhost

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: <1350405787.3954.1229.camel@edumazet-glaptop>
Date:	Tue, 16 Oct 2012 18:43:07 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Jan Hinnerk Stosch <janhinnerk.stosch@...il.com>
Cc:	netdev@...r.kernel.org
Subject: Re: regression when connecting to ipv6 localhost

On Tue, 2012-10-16 at 18:07 +0200, Jan Hinnerk Stosch wrote:
> 2012/10/15 Jan Hinnerk Stosch <janhinnerk.stosch@...il.com>:
> >
> > Yes. Attached..
> 
> Today I read about the existence of the "git bisect" function and if I
> have not done anything wrong the "bad commit" which lead to this
> regression is ddbe503203855939946430e39bae58de11b70b69.
> Perhaps this can help you.

Interesting, I was about to ask you to do a bisection ;)

So the hash value of ::1 was changed, and it has bad effect on your
machine...

Could it be hash collision and an old bug being uncovered ?

Could you trace inet6_addr_hash() a bit ?

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index d7c56f8..096c04c 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -580,7 +580,10 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
 
 static u32 inet6_addr_hash(const struct in6_addr *addr)
 {
-	return hash_32(ipv6_addr_hash(addr), IN6_ADDR_HSIZE_SHIFT);
+	u32 res = hash_32(ipv6_addr_hash(addr), IN6_ADDR_HSIZE_SHIFT);
+
+	pr_err("inet6_addr_hash(%pi6) %u\n", addr, res);
+	return res;
 }
 
 /* On success it returns ifp with increased reference count */


--
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