Messages in this thread |  | | From | David Laight <> | Subject | RE: [PATCH] netlink: don't copy over empty attribute data | Date | Wed, 22 Oct 2014 08:55:51 +0000 |
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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 > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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