[PATCH 6.3 076/286] rtnetlink: move IFLA_GSO_ tb check to validate_linkmsg

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Xin Long <lucien.xin@xxxxxxxxx>

[ Upstream commit fef5b228dd38378148bc850f7e69a7783f3b95a4 ]

These IFLA_GSO_* tb check should also be done for the new created link,
otherwise, they can be set to a huge value when creating links:

  # ip link add dummy1 gso_max_size 4294967295 type dummy
  # ip -d link show dummy1
    dummy addrgenmode eui64 ... gso_max_size 4294967295

Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation")
Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device")
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/core/rtnetlink.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f37deb18dd02e..7094569009b14 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2382,6 +2382,25 @@ static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[],
 		if (tb[IFLA_BROADCAST] &&
 		    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
 			return -EINVAL;
+
+		if (tb[IFLA_GSO_MAX_SIZE] &&
+		    nla_get_u32(tb[IFLA_GSO_MAX_SIZE]) > dev->tso_max_size) {
+			NL_SET_ERR_MSG(extack, "too big gso_max_size");
+			return -EINVAL;
+		}
+
+		if (tb[IFLA_GSO_MAX_SEGS] &&
+		    (nla_get_u32(tb[IFLA_GSO_MAX_SEGS]) > GSO_MAX_SEGS ||
+		     nla_get_u32(tb[IFLA_GSO_MAX_SEGS]) > dev->tso_max_segs)) {
+			NL_SET_ERR_MSG(extack, "too big gso_max_segs");
+			return -EINVAL;
+		}
+
+		if (tb[IFLA_GSO_IPV4_MAX_SIZE] &&
+		    nla_get_u32(tb[IFLA_GSO_IPV4_MAX_SIZE]) > dev->tso_max_size) {
+			NL_SET_ERR_MSG(extack, "too big gso_ipv4_max_size");
+			return -EINVAL;
+		}
 	}
 
 	if (tb[IFLA_AF_SPEC]) {
@@ -2855,11 +2874,6 @@ static int do_setlink(const struct sk_buff *skb,
 	if (tb[IFLA_GSO_MAX_SIZE]) {
 		u32 max_size = nla_get_u32(tb[IFLA_GSO_MAX_SIZE]);
 
-		if (max_size > dev->tso_max_size) {
-			err = -EINVAL;
-			goto errout;
-		}
-
 		if (dev->gso_max_size ^ max_size) {
 			netif_set_gso_max_size(dev, max_size);
 			status |= DO_SETLINK_MODIFIED;
@@ -2869,11 +2883,6 @@ static int do_setlink(const struct sk_buff *skb,
 	if (tb[IFLA_GSO_MAX_SEGS]) {
 		u32 max_segs = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]);
 
-		if (max_segs > GSO_MAX_SEGS || max_segs > dev->tso_max_segs) {
-			err = -EINVAL;
-			goto errout;
-		}
-
 		if (dev->gso_max_segs ^ max_segs) {
 			netif_set_gso_max_segs(dev, max_segs);
 			status |= DO_SETLINK_MODIFIED;
@@ -2892,11 +2901,6 @@ static int do_setlink(const struct sk_buff *skb,
 	if (tb[IFLA_GSO_IPV4_MAX_SIZE]) {
 		u32 max_size = nla_get_u32(tb[IFLA_GSO_IPV4_MAX_SIZE]);
 
-		if (max_size > dev->tso_max_size) {
-			err = -EINVAL;
-			goto errout;
-		}
-
 		if (dev->gso_ipv4_max_size ^ max_size) {
 			netif_set_gso_ipv4_max_size(dev, max_size);
 			status |= DO_SETLINK_MODIFIED;
-- 
2.39.2