From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri, 4 Aug 2023 14:04:36 +0000 (+0200)
Subject: ipc: linux: enforce IFNAMSIZ limit
X-Git-Tag: v1.0.20250521~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=13f4ac4cb74b5a833fa7f825ba785b1e5774e84f;p=thirdparty%2Fwireguard-tools.git

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 <Jason@zx2c4.com>
---

diff --git a/src/ipc-linux.h b/src/ipc-linux.h
index 5883ffe..d29c0c5 100644
--- 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));