From: Eric Dumazet <edumazet@google.com> stable inclusion from linux-4.19.211 commit 8cf8286ff286716ad61cef5d2a647faeb218d081 -------------------------------- [ 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: 10c9ead9f3c6 ("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> Acked-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- net/core/rtnetlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 055fd09ac1114..83de32e34bb55 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4512,7 +4512,7 @@ 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)); -- 2.25.1