From: Eric Dumazet edumazet@google.com
[ 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 --- 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 662eb1c37f47..10e2a0e4804b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5265,7 +5265,7 @@ nla_put_failure: 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));