ipc: linux: enforce IFNAMSIZ limit

libmnl doesn't check lengths, so do our own checking before copying the interface name to the netlink buffer. Signed-off-by: Jason A. Donenfeld <[email protected]>
WireGuard · Aug 4, 2023 · 13f4ac4 · 13f4ac4 · Neustradamus · Aug 26, 2023
1 parent 729242a
commit 13f4ac4
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/src/ipc-linux.h b/src/ipc-linux.h
@@ -479,6 +479,12 @@ static int kernel_get_device(struct wgdevice **device, const char *iface)
 	struct nlmsghdr *nlh;
 	struct mnlg_socket *nlg;
 
+	/* libmnl doesn't check the buffer size, so enforce that before using. */
+	if (strlen(iface) >= IFNAMSIZ) {
+		errno = ENAMETOOLONG;
+		return -ENAMETOOLONG;
+	}
+
 try_again:
 	ret = 0;
 	*device = calloc(1, sizeof(**device));