File CVE-2019-9824-qemut-slirp-check-sscanf-result-when-emulating-id.patch of Package xen.23721

References: bsc#1129623

When emulating ident in tcp_emu, if the strchr checks passed but the
sscanf check failed, two uninitialized variables would be copied and
sent in the reply, so move this code inside the if(sscanf()) clause.

Signed-off-by: William Bowling <address@hidden>
Cc: address@hidden
Cc: address@hidden
Message-Id: <address@hidden>
Signed-off-by: Samuel Thibault <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
---
 slirp/tcp_subr.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Index: xen-4.7.6-testing/tools/qemu-xen-traditional-dir-remote/slirp/tcp_subr.c
===================================================================
--- xen-4.7.6-testing.orig/tools/qemu-xen-traditional-dir-remote/slirp/tcp_subr.c
+++ xen-4.7.6-testing/tools/qemu-xen-traditional-dir-remote/slirp/tcp_subr.c
@@ -673,12 +673,12 @@ tcp_emu(so, m)
 							break;
 						}
 					}
+                                        so_rcv->sb_cc = snprintf(so_rcv->sb_data,
+                                                                 so_rcv->sb_datalen,
+                                                                 "%d,%d\r\n", n1, n2);
+				        so_rcv->sb_rptr = so_rcv->sb_data;
+				        so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
 				}
-                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
-                                                         so_rcv->sb_datalen,
-                                                         "%d,%d\r\n", n1, n2);
-				so_rcv->sb_rptr = so_rcv->sb_data;
-				so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
 			}
 			m_free(m);
 			return 0;