From: Thomas Graf Date: Thu, 11 Nov 2010 15:47:59 +0000 (+0000) Subject: rtnetlink: Fix message size calculation for link messages X-Git-Tag: v2.6.37-rc2~20^2~22 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=369cf77a6a3e41b1110506ddf43d45804103bfde;p=platform%2Fkernel%2Flinux-3.10.git rtnetlink: Fix message size calculation for link messages nlmsg_total_size() calculates the length of a netlink message including header and alignment. nla_total_size() calculates the space an individual attribute consumes which was meant to be used in this context. Also, ensure to account for the attribute header for the IFLA_INFO_XSTATS attribute as implementations of get_xstats_size() seem to assume that we do so. The addition of two message headers minus the missing attribute header resulted in a calculated message size that was larger than required. Therefore we never risked running out of skb tailroom. Signed-off-by: Thomas Graf Acked-by: Patrick McHardy Signed-off-by: David S. Miller --- diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8121268..841c287 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -347,16 +347,17 @@ static size_t rtnl_link_get_size(const struct net_device *dev) if (!ops) return 0; - size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */ - nlmsg_total_size(strlen(ops->kind) + 1); /* IFLA_INFO_KIND */ + size = nla_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */ + nla_total_size(strlen(ops->kind) + 1); /* IFLA_INFO_KIND */ if (ops->get_size) /* IFLA_INFO_DATA + nested data */ - size += nlmsg_total_size(sizeof(struct nlattr)) + + size += nla_total_size(sizeof(struct nlattr)) + ops->get_size(dev); if (ops->get_xstats_size) - size += ops->get_xstats_size(dev); /* IFLA_INFO_XSTATS */ + /* IFLA_INFO_XSTATS */ + size += nla_total_size(ops->get_xstats_size(dev)); return size; }