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-rw-r--r--include/uapi/linux/if_link.h1
-rw-r--r--net/core/rtnetlink.c19
2 files changed, 20 insertions, 0 deletions
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index bb3a90b57199..5ffdcb34e35b 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -155,6 +155,7 @@ enum {
IFLA_PROTO_DOWN,
IFLA_GSO_MAX_SEGS,
IFLA_GSO_MAX_SIZE,
+ IFLA_PAD,
__IFLA_MAX
};
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a7a3d345134a..198ca2c99510 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -878,6 +878,9 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
+ nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
+ nla_total_size(sizeof(struct rtnl_link_ifmap))
+ nla_total_size(sizeof(struct rtnl_link_stats))
+#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS
+ + nla_total_size(0) /* IFLA_PAD */
+#endif
+ nla_total_size(sizeof(struct rtnl_link_stats64))
+ nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
+ nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
@@ -1052,6 +1055,22 @@ static noinline_for_stack int rtnl_fill_stats(struct sk_buff *skb,
struct rtnl_link_stats64 *sp;
struct nlattr *attr;
+#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS
+ /* IF necessary, add a zero length NOP attribute so that the
+ * nla_data() of the IFLA_STATS64 will be 64-bit aligned.
+ *
+ * The nlattr header is 4 bytes in size, that's why we test
+ * if the skb->data _is_ aligned. This NOP attribute, plus
+ * nlattr header for IFLA_STATS64, will make nla_data() 8-byte
+ * aligned.
+ */
+ if (IS_ALIGNED((unsigned long)skb->data, 8)) {
+ attr = nla_reserve(skb, IFLA_PAD, 0);
+ if (!attr)
+ return -EMSGSIZE;
+ }
+#endif
+
attr = nla_reserve(skb, IFLA_STATS64,
sizeof(struct rtnl_link_stats64));
if (!attr)