[RFC PATCH 19/20] netlink: use new strict length types in policy for 5.2

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Taken from
https://git.zx2c4.com/WireGuard/commit/src?id=3120425f69003be287cb2d308f89c7a6a0335ff0

Reported-by: Bruno Wolff III <bruno@wolff.to>
---
 drivers/net/wireguard/netlink.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 3763e8c14ea5..676d36725120 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -21,8 +21,8 @@ static struct genl_family genl_family;
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= { .len = NOISE_PUBLIC_KEY_LEN },
-	[WGDEVICE_A_PUBLIC_KEY]		= { .len = NOISE_PUBLIC_KEY_LEN },
+	[WGDEVICE_A_PRIVATE_KEY]	= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
+	[WGDEVICE_A_PUBLIC_KEY]		= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
 	[WGDEVICE_A_FLAGS]		= { .type = NLA_U32 },
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
@@ -30,12 +30,12 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= { .len = NOISE_PUBLIC_KEY_LEN },
-	[WGPEER_A_PRESHARED_KEY]			= { .len = NOISE_SYMMETRIC_KEY_LEN },
+	[WGPEER_A_PUBLIC_KEY]				= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
+	[WGPEER_A_PRESHARED_KEY]			= { .type = NLA_EXACT_LEN, .len = NOISE_SYMMETRIC_KEY_LEN },
 	[WGPEER_A_FLAGS]				= { .type = NLA_U32 },
-	[WGPEER_A_ENDPOINT]				= { .len = sizeof(struct sockaddr) },
+	[WGPEER_A_ENDPOINT]				= { .type = NLA_MIN_LEN, .len = sizeof(struct sockaddr) },
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
-	[WGPEER_A_LAST_HANDSHAKE_TIME]			= { .len = sizeof(struct __kernel_timespec) },
+	[WGPEER_A_LAST_HANDSHAKE_TIME]			= { .type = NLA_EXACT_LEN, .len = sizeof(struct __kernel_timespec) },
 	[WGPEER_A_RX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_TX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_ALLOWEDIPS]				= { .type = NLA_NESTED },
@@ -44,7 +44,7 @@ static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
 
 static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1] = {
 	[WGALLOWEDIP_A_FAMILY]		= { .type = NLA_U16 },
-	[WGALLOWEDIP_A_IPADDR]		= { .len = sizeof(struct in_addr) },
+	[WGALLOWEDIP_A_IPADDR]		= { .type = NLA_MIN_LEN, .len = sizeof(struct in_addr) },
 	[WGALLOWEDIP_A_CIDR_MASK]	= { .type = NLA_U8 }
 };
 
@@ -591,12 +591,10 @@ static const struct genl_ops genl_ops[] = {
 		.start = wg_get_device_start,
 		.dumpit = wg_get_device_dump,
 		.done = wg_get_device_done,
-		.policy = device_policy,
 		.flags = GENL_UNS_ADMIN_PERM
 	}, {
 		.cmd = WG_CMD_SET_DEVICE,
 		.doit = wg_set_device,
-		.policy = device_policy,
 		.flags = GENL_UNS_ADMIN_PERM
 	}
 };
@@ -608,6 +606,7 @@ static struct genl_family genl_family __ro_after_init = {
 	.version = WG_GENL_VERSION,
 	.maxattr = WGDEVICE_A_MAX,
 	.module = THIS_MODULE,
+	.policy = device_policy,
 	.netnsok = true
 };
 
-- 
2.17.1