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authorPetr Machata <petrm@nvidia.com>2022-04-12 22:25:06 +0200
committerPaolo Abeni <pabeni@redhat.com>2022-04-14 09:01:26 +0200
commit23cfe941b52e2fa645bdfd770087128a74c7dbee (patch)
treec2890ee41df25a3c1d8e12e783aa8c93959d13b3
parent00fa91bc9cc2a9d340f963af5e457610ad4b2f9c (diff)
rtnetlink: Fix handling of disabled L3 stats in RTM_GETSTATS replies
When L3 stats are disabled, rtnl_offload_xstats_get_size_stats() returns size of 0, which is supposed to be an indication that the corresponding attribute should not be emitted. However, instead, the current code reserves a 0-byte attribute. The reason this does not show up as a citation on a kasan kernel is that netdev_offload_xstats_get(), which is supposed to fill in the data, never ends up getting called, because rtnl_offload_xstats_get_stats() notices that the stats are not actually used and skips the call. Thus a zero-length IFLA_OFFLOAD_XSTATS_L3_STATS attribute ends up in a response, confusing the userspace. Fix by skipping the L3-stats related block in rtnl_offload_xstats_fill(). Fixes: 0e7788fd7622 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats") Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/591b58e7623edc3eb66dd1fcfa8c8f133d090974.1649794741.git.petrm@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r--net/core/rtnetlink.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 159c9c61e6af..d1381ea6d52e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -5242,6 +5242,8 @@ static int rtnl_offload_xstats_fill(struct sk_buff *skb, struct net_device *dev,
*prividx = attr_id_l3_stats;
size_l3 = rtnl_offload_xstats_get_size_stats(dev, t_l3);
+ if (!size_l3)
+ goto skip_l3_stats;
attr = nla_reserve_64bit(skb, attr_id_l3_stats, size_l3,
IFLA_OFFLOAD_XSTATS_UNSPEC);
if (!attr)
@@ -5253,6 +5255,7 @@ static int rtnl_offload_xstats_fill(struct sk_buff *skb, struct net_device *dev,
return err;
have_data = true;
+skip_l3_stats:
*prividx = 0;
}