From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59061) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cr0q9-0007eS-Ix for qemu-devel@nongnu.org; Thu, 23 Mar 2017 07:23:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cr0q4-00039p-Mj for qemu-devel@nongnu.org; Thu, 23 Mar 2017 07:23:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41474) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cr0q4-000381-H3 for qemu-devel@nongnu.org; Thu, 23 Mar 2017 07:23:32 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 69F7861D33 for ; Thu, 23 Mar 2017 11:23:32 +0000 (UTC) From: Markus Armbruster Date: Thu, 23 Mar 2017 12:23:28 +0100 Message-Id: <1490268208-23368-1-git-send-email-armbru@redhat.com> Subject: [Qemu-devel] [PATCH for-2.9] sockets: Fix socket_address_to_string() hostname truncation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: berrange@redhat.com, kraxel@redhat.com, pbonzini@redhat.com We first snprintf() to a fixed buffer, then g_strdup() the result *boggle*. Worse, the size of the fixed buffer INET6_ADDRSTRLEN + 5 + 4 is bogus: the 4 correctly accounts for '[', ']', ':' and '\0', but INET6_ADDRSTRLEN is not a suitable limit for inet->host, and 5 is not one for inet->port! They are for host and port in *numeric* form (exploiting that INET6_ADDRSTRLEN > INET_ADDRSTRLEN), but inet->host can also be a hostname, and inet->port can be a service name, to be resolved with getaddrinfo(). Fortunately, the only user so far is the "socket" network backend's net_socket_connected(), which uses it to initialize a NetSocketState's info_str[]. info_str[] has considerable more space: 256 instead of 55. So the bug's impact appears to be limited to truncated "info networks" with the "socket" network backend. The fix is obvious: use g_strdup_printf(). Signed-off-by: Markus Armbruster --- util/qemu-sockets.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index 7c120c4..40164bf 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -1307,19 +1307,14 @@ char *socket_address_to_string(struct SocketAddress *addr, Error **errp) { char *buf; InetSocketAddress *inet; - char host_port[INET6_ADDRSTRLEN + 5 + 4]; switch (addr->type) { case SOCKET_ADDRESS_KIND_INET: inet = addr->u.inet.data; if (strchr(inet->host, ':') == NULL) { - snprintf(host_port, sizeof(host_port), "%s:%s", inet->host, - inet->port); - buf = g_strdup(host_port); + buf = g_strdup_printf("%s:%s", inet->host, inet->port); } else { - snprintf(host_port, sizeof(host_port), "[%s]:%s", inet->host, - inet->port); - buf = g_strdup(host_port); + buf = g_strdup_printf("[%s]:%s", inet->host, inet->port); } break; -- 2.7.4