[v4_1_esv] Clean up interface name handling during interface discovery

    Merges in rt42226.

diff --git a/RELNOTES b/RELNOTES
index 031f7cd919250276ce78cb68efcecfc1e6bb6a28..0dc1ae3cac422d5096ffddacbb4fd56e17a64eea 100644 (file)
--- a/RELNOTES
+++ b/RELNOTES
@@ -87,6 +87,12 @@ by Eric Young (eay@cryptsoft.com).
   enabled) prior to offering an abandoned lease to client.
   [ISC-Bugs #41815]
 
+- Correct handling of interface names during interface discovery. This
+  addresses an issue where interface names of 15 characters in length
+  could lead to crashes or interface recognition errors during startup
+  of dhcpd, dhclient, and dhcrelay.
+  [ISC-Bugs #42226]
+
                        Changes since 4.1-ESV-R13b1
 
 - None

diff --git a/common/discover.c b/common/discover.c
index ea5a82b1cd3d42544e24acae0a9f29ab2df7127f..da0c3f81d61de6b3e8a0ca14265c54913aa00655 100644 (file)
--- a/common/discover.c
+++ b/common/discover.c
@@ -332,8 +332,8 @@ next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
                        continue;
                }
 
-               strcpy(info->name, p->lifr_name);
-               memset(&info->addr, 0, sizeof(info->addr));
+               memset(info, 0, sizeof(struct iface_info));
+               strncpy(info->name, p->lifr_name, sizeof(info->name) - 1);
                memcpy(&info->addr, &p->lifr_addr, sizeof(p->lifr_addr));
 
 #if defined(sun) || defined(__linux)
@@ -349,7 +349,7 @@ next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
                 (strncmp(info->name, "dummy", 5) == 0));
        
        memset(&tmp, 0, sizeof(tmp));
-       strcpy(tmp.lifr_name, info->name);
+       strncpy(tmp.lifr_name, info->name, sizeof(tmp.lifr_name) - 1);
        if (ioctl(ifaces->sock, SIOCGLIFFLAGS, &tmp) < 0) {
                log_error("Error getting interface flags for '%s'; %m", 
                          p->lifr_name);
@@ -664,7 +664,7 @@ next_iface6(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
                        log_error("IPv6 interface name '%s' too long", name);
                        return 0;
                }
-               strcpy(info->name, name);
+               strncpy(info->name, name, sizeof(info->name) - 1);
 
 #ifdef SKIP_DUMMY_INTERFACES
        } while (strncmp(info->name, "dummy", 5) == 0);
@@ -702,7 +702,7 @@ next_iface6(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
         * Get our flags.
         */
        memset(&tmp, 0, sizeof(tmp));
-       strcpy(tmp.ifr_name, name);
+       strncpy(tmp.ifr_name, name, sizeof(tmp.ifr_name) - 1);
        if (ioctl(ifaces->sock, SIOCGIFFLAGS, &tmp) < 0) {
                log_error("Error getting interface flags for '%s'; %m", name);
                *err = 1;
@@ -723,6 +723,7 @@ next_iface6(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
  */
 int
 next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
+       memset(info, 0, sizeof(struct iface_info));
        if (next_iface4(info, err, ifaces)) {
                return 1;
        }
@@ -815,7 +816,8 @@ next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
                *err = 1;
                return 0;
        }
-       strcpy(info->name, ifaces->next->ifa_name);
+       memset(info, 0, sizeof(struct iface_info));
+       strncpy(info->name, ifaces->next->ifa_name, sizeof(info->name) - 1);
        memcpy(&info->addr, ifaces->next->ifa_addr, 
               ifaces->next->ifa_addr->sa_len);
        info->flags = ifaces->next->ifa_flags;
@@ -984,7 +986,7 @@ discover_interfaces(int state) {
                                log_fatal("Error allocating interface %s: %s",
                                          info.name, isc_result_totext(status));
                        }
-                       strcpy(tmp->name, info.name);
+                       strncpy(tmp->name, info.name, sizeof(tmp->name) - 1);
                        interface_snorf(tmp, ir);
                        interface_dereference(&tmp, MDL);
                        tmp = interfaces; /* XXX */