solaris/open_tun: prevent crash when dev is empty string

This was originally reported on GH, but never dealt with.
Make sure 'ptr' is always initialized to prevent derefence of null
pointer in case of empty dev string.

While at it, change the if condition to use ptr instead of dev, since
dev is not used anymore in the logic.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20220917125811.13549-1-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25235.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 2acd008203cfa1626b9347391663c1ea6c9c561b..5ea460a6431c9d7b7c711fdb7fc52d51046e797f 100644 (file)
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -2379,10 +2379,11 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun
         msg(M_ERR, "Can't open %s", dev_node);
     }
 
+    ptr = dev;
+
     /* get unit number */
-    if (*dev)
+    if (*ptr)
     {
-        ptr = dev;
         while (*ptr && !isdigit((int) *ptr))
         {
             ptr++;