This is a note to let you know that I've just added the patch titled
rtnetlink: fix if_nlmsg_stats_size() under estimation
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rtnetlink-fix-if_nlmsg_stats_size-under-estimation.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8c12182633d5805d3bf9619804c556cc7f7fc534
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Tue Oct 5 14:04:17 2021 -0700
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: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Roopa Prabhu <roopa@xxxxxxxxxx>
Acked-by: Roopa Prabhu <roopa@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 911752e8a3e6..012143f313a8 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3900,7 +3900,7 @@ 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));
