Merge branch 'wireguard-patches-for-5-18-rc1'

Jason A. Donenfeld says:

====================
wireguard patches for 5.18-rc1

Here's a small set of fixes for the next net push:

1) Pipacs reported a CFI violation in a cleanup routine, which he
   triggered using grsec's RAP. I haven't seen reports of this yet from
   the Android/CFI world yet, but it's only a matter of time there.

2) A small rng cleanup to the self test harness to make it initialize
   faster on 5.18.

3) Wang reported and fixed a skb leak for CONFIG_IPV6=n.

4) After Wang's fix for the direct leak, I investigated how that code
   path even could be hit, and found that the netlink layer still
   handles IPv6 endpoints, when it probably shouldn't.
====================

Link: https://lore.kernel.org/r/20220330013127.426620-1-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/net/wireguard/queueing.c

@@ -4,6 +4,7 @@
  */
 
 #include "queueing.h"
+#include <linux/skb_array.h>
 
 struct multicore_worker __percpu *
 wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr)
@@ -42,7 +43,7 @@ void wg_packet_queue_free(struct crypt_queue *queue, bool purge)
 {
 	free_percpu(queue->worker);
 	WARN_ON(!purge && !__ptr_ring_empty(&queue->ring));
-	ptr_ring_cleanup(&queue->ring, purge ? (void(*)(void*))kfree_skb : NULL);
+	ptr_ring_cleanup(&queue->ring, purge ? __skb_array_destroy_skb : NULL);
 }
 
 #define NEXT(skb) ((skb)->prev)

drivers/net/wireguard/socket.c

@@ -160,6 +160,7 @@ static int send6(struct wg_device *wg, struct sk_buff *skb,
 	rcu_read_unlock_bh();
 	return ret;
 #else
+	kfree_skb(skb);
 	return -EAFNOSUPPORT;
 #endif
 }
@@ -241,7 +242,7 @@ int wg_socket_endpoint_from_skb(struct endpoint *endpoint,
 		endpoint->addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 		endpoint->src4.s_addr = ip_hdr(skb)->daddr;
 		endpoint->src_if4 = skb->skb_iif;
-	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+	} else if (IS_ENABLED(CONFIG_IPV6) && skb->protocol == htons(ETH_P_IPV6)) {
 		endpoint->addr6.sin6_family = AF_INET6;
 		endpoint->addr6.sin6_port = udp_hdr(skb)->source;
 		endpoint->addr6.sin6_addr = ipv6_hdr(skb)->saddr;
@@ -284,7 +285,7 @@ void wg_socket_set_peer_endpoint(struct wg_peer *peer,
 		peer->endpoint.addr4 = endpoint->addr4;
 		peer->endpoint.src4 = endpoint->src4;
 		peer->endpoint.src_if4 = endpoint->src_if4;
-	} else if (endpoint->addr.sa_family == AF_INET6) {
+	} else if (IS_ENABLED(CONFIG_IPV6) && endpoint->addr.sa_family == AF_INET6) {
 		peer->endpoint.addr6 = endpoint->addr6;
 		peer->endpoint.src6 = endpoint->src6;
 	} else {

tools/testing/selftests/wireguard/qemu/init.c

@@ -56,26 +56,14 @@ static void print_banner(void)
 
 static void seed_rng(void)
 {
-	int fd;
-	struct {
-		int entropy_count;
-		int buffer_size;
-		unsigned char buffer[256];
-	} entropy = {
-		.entropy_count = sizeof(entropy.buffer) * 8,
-		.buffer_size = sizeof(entropy.buffer),
-		.buffer = "Adding real entropy is not actually important for these tests. Don't try this at home, kids!"
-	};
+	int bits = 256, fd;
 
-	if (mknod("/dev/urandom", S_IFCHR | 0644, makedev(1, 9)))
-		panic("mknod(/dev/urandom)");
-	fd = open("/dev/urandom", O_WRONLY);
+	pretty_message("[+] Fake seeding RNG...");
+	fd = open("/dev/random", O_WRONLY);
 	if (fd < 0)
-		panic("open(urandom)");
-	for (int i = 0; i < 256; ++i) {
-		if (ioctl(fd, RNDADDENTROPY, &entropy) < 0)
-			panic("ioctl(urandom)");
-	}
+		panic("open(random)");
+	if (ioctl(fd, RNDADDTOENTCNT, &bits) < 0)
+		panic("ioctl(RNDADDTOENTCNT)");
 	close(fd);
 }
 
@@ -270,10 +258,10 @@ static void check_leaks(void)
 
 int main(int argc, char *argv[])
 {
-	seed_rng();
 	ensure_console();
 	print_banner();
 	mount_filesystems();
+	seed_rng();
 	kmod_selftests();
 	enable_logging();
 	clear_leaks();