[PATCH net-next v3 01/11] wireguard: netlink: validate nested arrays in policy

Asbjørn Sloth Tønnesen
2025-11-05T18:33:04Z

Use NLA_POLICY_NESTED_ARRAY() to perform nested array validation
in the policy validation step.

The nested policy was already enforced through nla_parse_nested(),
however extack wasn't passed previously.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
drivers/net/wireguard/netlink.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 67f962eb8b46..e4416f23d427 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -18,6 +18,8 @@
#include <crypto/utils.h>

static struct genl_family genl_family;
+static const struct nla_policy peer_policy[WGPEER_A_MAX + 1];
+static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1];

static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
[WGDEVICE_A_IFINDEX] = { .type = NLA_U32 },
@@ -27,7 +29,7 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
[WGDEVICE_A_FLAGS] = NLA_POLICY_MASK(NLA_U32, __WGDEVICE_F_ALL),
[WGDEVICE_A_LISTEN_PORT] = { .type = NLA_U16 },
[WGDEVICE_A_FWMARK] = { .type = NLA_U32 },
- [WGDEVICE_A_PEERS] = { .type = NLA_NESTED }
+ [WGDEVICE_A_PEERS] = NLA_POLICY_NESTED_ARRAY(peer_policy),
};

static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
@@ -39,7 +41,7 @@ static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
[WGPEER_A_LAST_HANDSHAKE_TIME] = NLA_POLICY_EXACT_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 },
+ [WGPEER_A_ALLOWEDIPS] = NLA_POLICY_NESTED_ARRAY(allowedip_policy),
[WGPEER_A_PROTOCOL_VERSION] = { .type = NLA_U32 }
};

@@ -467,7 +469,7 @@ static int set_peer(struct wg_device *wg, struct nlattr **attrs)

nla_for_each_nested(attr, attrs[WGPEER_A_ALLOWEDIPS], rem) {
ret = nla_parse_nested(allowedip, WGALLOWEDIP_A_MAX,
- attr, allowedip_policy, NULL);
+ attr, NULL, NULL);
if (ret < 0)
goto out;
ret = set_allowedip(peer, allowedip);
@@ -593,7 +595,7 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)

nla_for_each_nested(attr, info->attrs[WGDEVICE_A_PEERS], rem) {
ret = nla_parse_nested(peer, WGPEER_A_MAX, attr,
- peer_policy, NULL);
+ NULL, NULL);
if (ret < 0)
goto out;
ret = set_peer(wg, peer);
--
2.51.0