ifplugd: more robust interface name match check

function                                             old     new   delta
check_existence_through_netlink                      278     308     +30

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index f398cca22..41b04c4ed 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -485,8 +485,10 @@ static smallint detect_link(void)
 
 static NOINLINE int check_existence_through_netlink(void)
 {
+        int iface_len;
         char replybuf[1024];
 
+        iface_len = strlen(G.iface);
         while (1) {
                 struct nlmsghdr *mhdr;
                 ssize_t bytes;
@@ -526,8 +528,9 @@ static NOINLINE int check_existence_through_netlink(void)
                                                 int len = RTA_PAYLOAD(attr);
                                                 if (len > IFNAMSIZ)
                                                         len = IFNAMSIZ;
-
-                                                if (strncmp(G.iface, RTA_DATA(attr), len) == 0) {
+                                                if (iface_len <= len
+                                                 && strncmp(G.iface, RTA_DATA(attr), len) == 0
+                                                ) {
                                                         G.iface_exists = (mhdr->nlmsg_type == RTM_NEWLINK);
                                                 }
                                         }