Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 23/28] rtnetlink: fix if_nlmsg_stats_size() under estimation | Date | Mon, 11 Oct 2021 15:47:13 +0200 |
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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
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