Fix denial of service - memory corruption.

[samba.git] / source3 / libaddns / dnssock.c

diff --git a/source3/libaddns/dnssock.c b/source3/libaddns/dnssock.c
index 7c8bd418e5765e5dc97ccd3e85a1c0dfb8aca1f9..bf11fea9313d4343fb599680a71a0ccb6909c202 100644 (file)
--- a/source3/libaddns/dnssock.c
+++ b/source3/libaddns/dnssock.c
@@ -219,6 +219,11 @@ static DNS_ERROR read_all(int fd, uint8 *data, size_t len)
                ssize_t ret;
                int fd_ready;
                
+               if (fd < 0 || fd >= FD_SETSIZE) {
+                       /* read timeout */
+                       return ERROR_DNS_SOCKET_ERROR;
+               }
+
                FD_ZERO( &rfds );
                FD_SET( fd, &rfds );