| From f97b359b8b63b7560806efa32ff873ddc9107c8d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 5 Oct 2021 14:04:17 -0700 |
| Subject: rtnetlink: fix if_nlmsg_stats_size() under estimation |
| |
| 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 055fd09ac111..83de32e34bb5 100644 |
| --- a/net/core/rtnetlink.c |
| +++ b/net/core/rtnetlink.c |
| @@ -4512,7 +4512,7 @@ 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)); |
| -- |
| 2.33.0 |
| |
