rtnetlink: fix if_nlmsg_stats_size() under estimation

[ Upstream commit d34367991933d28bd7331f67a759be9a8c474014 ]

rtnl_fill_statsinfo() is filling skb with one mandatory if_stats_msg structure.

nlmsg_put(skb, pid, seq, type, sizeof(struct if_stats_msg), flags);

But if_nlmsg_stats_size() never considered the needed storage.

This bug did not show up because alloc_skb(X) allocates skb with
extra tailroom, because of added alignments. This could very well
be changed in the future to have deterministic behavior.

Fixes: 10c9ead9f3 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Eric Dumazet 2021-10-05 14:04:17 -07:00 committed by Greg Kroah-Hartman
parent 72c2a68f1d
commit 9a04302252

View File

@ -5257,7 +5257,7 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
static size_t if_nlmsg_stats_size(const struct net_device *dev,
u32 filter_mask)
{
size_t size = 0;
size_t size = NLMSG_ALIGN(sizeof(struct if_stats_msg));
if (stats_attr_valid(filter_mask, IFLA_STATS_LINK_64, 0))
size += nla_total_size_64bit(sizeof(struct rtnl_link_stats64));