From: David Laight <David.Laight@ACULAB.COM>
To: 'Sasha Levin' <sasha.levin@oracle.com>,
"davem@davemloft.net" <davem@davemloft.net>
Cc: "a.ryabinin@samsung.com" <a.ryabinin@samsung.com>,
"pablo@netfilter.org" <pablo@netfilter.org>,
"mschmidt@redhat.com" <mschmidt@redhat.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: RE: [PATCH] netlink: don't copy over empty attribute data
Date: Wed, 22 Oct 2014 08:55:51 +0000 [thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1C9DCF6A@AcuExch.aculab.com> (raw)
In-Reply-To: <1413924669-26732-1-git-send-email-sasha.levin@oracle.com>
From: Sasha Levin
> netlink uses empty data to seperate different levels. However, we still
> try to copy that data from a NULL ptr using memcpy, which is an undefined
> behaviour.
>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
> lib/nlattr.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/nlattr.c b/lib/nlattr.c
> index 9c3e85f..6512b43 100644
> --- a/lib/nlattr.c
> +++ b/lib/nlattr.c
> @@ -430,7 +430,8 @@ void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
> struct nlattr *nla;
>
> nla = __nla_reserve(skb, attrtype, attrlen);
> - memcpy(nla_data(nla), data, attrlen);
> + if (data)
> + memcpy(nla_data(nla), data, attrlen);
Were it even appropriate to add a conditional here, the correct
check would be against 'attrlen', not 'data'.
David
> }
> EXPORT_SYMBOL(__nla_put);
>
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2014-10-22 8:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 20:51 [PATCH] netlink: don't copy over empty attribute data Sasha Levin
2014-10-22 1:39 ` David Miller
2014-10-22 2:19 ` Sasha Levin
2014-10-22 6:15 ` David Miller
2014-10-26 23:32 ` Sasha Levin
2014-10-27 2:03 ` David Miller
2014-10-27 14:42 ` Sasha Levin
2014-10-27 16:46 ` Andrey Ryabinin
2014-10-22 8:55 ` David Laight [this message]
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