Merge pull request #570 from pi-hole/hotfix/v4.3.1

Hotfix v4.3.1

networktable.c

@@ -116,7 +116,6 @@ void parse_arp_cache(void)
  // unknown (only DNS requesting clients do this)
  lock_shm();
  int clientID = findClientID(ip, false);
- unlock_shm();
 
  // This client is known (by its IP address) to pihole-FTL if
  // findClientID() returned a non-negative index
@@ -177,6 +176,8 @@ void parse_arp_cache(void)
  // else:
  // Device in database but not known to Pi-hole: No action required
 
+ unlock_shm();
+
  // Count number of processed ARP cache entries
  entries++;
  }

resolve.c

@@ -66,10 +66,11 @@ static char *resolveHostname(const char *addr)
 // Resolve upstream destination host names
 static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
 {
- // Get IP and host name strings
+ // Get IP and host name strings. They are cloned in case shared memory is
+ // resized before the next lock
  lock_shm();
- const char* ipaddr = getstr(ippos);
- const char* oldname = getstr(oldnamepos);
+ char* ipaddr = strdup(getstr(ippos));
+ char* oldname = strdup(getstr(oldnamepos));
  unlock_shm();
 
  // Important: Don't hold a lock while resolving as the main thread
@@ -86,6 +87,8 @@ static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
  // newname has already been checked against NULL
  // so we can safely free it
  free(newname);
+ free(ipaddr);
+ free(oldname);
  unlock_shm();
  return newnamepos;
  }
@@ -95,6 +98,9 @@ static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
  logg("Not adding \"%s\" to buffer (unchanged)", oldname);
  }
 
+ free(ipaddr);
+ free(oldname);
+
  // Not changed, return old namepos
  return oldnamepos;
 }