File CVE-2016-9578-remote-dos-via-crafted-message.patch of Package spice.4104

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File CVE-2016-9578-remote-dos-via-crafted-message.patch of Package spice.4104

From fb8760d657271f52b357f83615c81bc984a3a197 Mon Sep 17 00:00:00 2001
From: Frediano Ziglio <fziglio@redhat.com>
Date: Mon, 28 Nov 2016 13:15:58 +0000
Subject: [PATCH spice-server] Prevent possible DoS attempts during protocol handshake

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
---
 server/reds.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: spice-0.12.7/server/reds.c
===================================================================
--- spice-0.12.7.orig/server/reds.c	2016-04-14 17:09:22.000000000 +0200
+++ spice-0.12.7/server/reds.c	2017-02-02 12:21:06.346289634 +0100
@@ -2110,6 +2110,14 @@ static void reds_handle_read_link_done(v
     link_mess->num_channel_caps = GUINT32_FROM_LE(link_mess->num_channel_caps);
     link_mess->num_common_caps = GUINT32_FROM_LE(link_mess->num_common_caps);
 
+    /* Prevent DoS. Currently we defined only 13 capabilities so here 1 would suffice,
+     * I expect 1024 to be valid for quite a lot time */
+    if (link_mess->num_channel_caps > 1024 || link_mess->num_common_caps > 1024) {
+        reds_send_link_error(link, SPICE_LINK_ERR_INVALID_DATA);
+        reds_link_free(link);
+        return;
+    }
+
     num_caps = link_mess->num_common_caps + link_mess->num_channel_caps;
     caps = (uint32_t *)((uint8_t *)link_mess + link_mess->caps_offset);
 
@@ -2202,7 +2210,8 @@ static void reds_handle_read_header_done
 
     reds->peer_minor_version = header->minor_version;
 
-    if (header->size < sizeof(SpiceLinkMess)) {
+    /* the check for 4096 is to avoid clients to attempt DoS to the server */
+    if (header->size < sizeof(SpiceLinkMess) || header->size > 4096) {
         reds_send_link_error(link, SPICE_LINK_ERR_INVALID_DATA);
         spice_warning("bad size %u", header->size);
         reds_link_free(link);

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File CVE-2016-9578-remote-dos-via-crafted-message.patch of Package spice.4104

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