Control: tags 868083 + patch
Control: tags 868083 + pending
Dear maintainer,
I've prepared an NMU for spice (versioned as 0.12.8-2.2) and
uploaded it to unstable without delay. Since the versions in Stretch
and Sid are identical, I have just applied the patches from the stable
version.
Regards,
Markus
diff -Nru spice-0.12.8/debian/changelog spice-0.12.8/debian/changelog
--- spice-0.12.8/debian/changelog 2017-02-13 21:42:01.000000000 +0100
+++ spice-0.12.8/debian/changelog 2017-07-21 23:34:38.000000000 +0200
@@ -1,3 +1,11 @@
+spice (0.12.8-2.2) unstable; urgency=medium
+
+ * Non-maintainer upload.
+ * Fix CVE-2017-7506: (Closes: #868083)
+ Possible buffer overflow via invalid monitor configurations.
+
+ -- Markus Koschany <a...@debian.org> Fri, 21 Jul 2017 23:34:38 +0200
+
spice (0.12.8-2.1) unstable; urgency=medium
* Non-maintainer upload.
diff -Nru spice-0.12.8/debian/patches/CVE-2017-7506-1.patch spice-0.12.8/debian/patches/CVE-2017-7506-1.patch
--- spice-0.12.8/debian/patches/CVE-2017-7506-1.patch 1970-01-01 01:00:00.000000000 +0100
+++ spice-0.12.8/debian/patches/CVE-2017-7506-1.patch 2017-07-21 23:34:38.000000000 +0200
@@ -0,0 +1,73 @@
+From 257f69d619fed407493156c8a7b952abc8a51314 Mon Sep 17 00:00:00 2001
+From: Frediano Ziglio <fzig...@redhat.com>
+Date: Mon, 15 May 2017 15:57:28 +0100
+Subject: [spice-server 1/3] reds: Disconnect when receiving overly big
+ ClientMonitorsConfig
+
+Total message size received from the client was unlimited. There is
+a 2kiB size check on individual agent messages, but the MonitorsConfig
+message can be split in multiple chunks, and the size of the
+non-chunked MonitorsConfig message was never checked. This could easily
+lead to memory exhaustion on the host.
+
+Signed-off-by: Frediano Ziglio <fzig...@redhat.com>
+---
+ server/reds.c | 25 +++++++++++++++++++++++--
+ 1 file changed, 23 insertions(+), 2 deletions(-)
+
+diff --git a/server/reds.c b/server/reds.c
+index f439a3668..7be85fdfc 100644
+--- a/server/reds.c
++++ b/server/reds.c
+@@ -993,19 +993,34 @@ static void reds_client_monitors_config_cleanup(void)
+ static void reds_on_main_agent_monitors_config(
+ MainChannelClient *mcc, void *message, size_t size)
+ {
++ const unsigned int MAX_MONITORS = 256;
++ const unsigned int MAX_MONITOR_CONFIG_SIZE =
++ sizeof(VDAgentMonitorsConfig) + MAX_MONITORS * sizeof(VDAgentMonConfig);
++
+ VDAgentMessage *msg_header;
+ VDAgentMonitorsConfig *monitors_config;
+ RedsClientMonitorsConfig *cmc = &reds->client_monitors_config;
+
++ // limit size of message sent by the client as this can cause a DoS through
++ // memory exhaustion, or potentially some integer overflows
++ if (sizeof(VDAgentMessage) + MAX_MONITOR_CONFIG_SIZE - cmc->buffer_size < size) {
++ goto overflow;
++ }
+ cmc->buffer_size += size;
+ cmc->buffer = realloc(cmc->buffer, cmc->buffer_size);
+ spice_assert(cmc->buffer);
+ cmc->mcc = mcc;
+ memcpy(cmc->buffer + cmc->buffer_pos, message, size);
+ cmc->buffer_pos += size;
++ if (sizeof(VDAgentMessage) > cmc->buffer_size) {
++ spice_debug("not enough data yet. %d", cmc->buffer_size);
++ return;
++ }
+ msg_header = (VDAgentMessage *)cmc->buffer;
+- if (sizeof(VDAgentMessage) > cmc->buffer_size ||
+- msg_header->size > cmc->buffer_size - sizeof(VDAgentMessage)) {
++ if (msg_header->size > MAX_MONITOR_CONFIG_SIZE) {
++ goto overflow;
++ }
++ if (msg_header->size > cmc->buffer_size - sizeof(VDAgentMessage)) {
+ spice_debug("not enough data yet. %d", cmc->buffer_size);
+ return;
+ }
+@@ -1013,6 +1028,12 @@ static void reds_on_main_agent_monitors_config(
+ spice_debug("%s: %d", __func__, monitors_config->num_of_monitors);
+ red_dispatcher_client_monitors_config(monitors_config);
+ reds_client_monitors_config_cleanup();
++ return;
++
++overflow:
++ spice_warning("received invalid MonitorsConfig request from client, disconnecting");
++ red_channel_client_disconnect(main_channel_client_get_base(mcc));
++ reds_client_monitors_config_cleanup();
+ }
+
+ void reds_on_main_agent_data(MainChannelClient *mcc, void *message, size_t size)
+--
+2.13.0
diff -Nru spice-0.12.8/debian/patches/CVE-2017-7506-2.patch spice-0.12.8/debian/patches/CVE-2017-7506-2.patch
--- spice-0.12.8/debian/patches/CVE-2017-7506-2.patch 1970-01-01 01:00:00.000000000 +0100
+++ spice-0.12.8/debian/patches/CVE-2017-7506-2.patch 2017-07-21 23:34:38.000000000 +0200
@@ -0,0 +1,29 @@
+From ff2b4ef70181087d5abd50bad76d026ec5088a93 Mon Sep 17 00:00:00 2001
+From: Frediano Ziglio <fzig...@redhat.com>
+Date: Mon, 15 May 2017 15:57:28 +0100
+Subject: [spice-server 2/3] reds: Avoid integer overflows handling monitor
+ configuration
+
+Avoid VDAgentMessage::size integer overflows.
+
+Signed-off-by: Frediano Ziglio <fzig...@redhat.com>
+---
+ server/reds.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/server/reds.c b/server/reds.c
+index 7be85fdfc..e1c8c1086 100644
+--- a/server/reds.c
++++ b/server/reds.c
+@@ -1024,6 +1024,9 @@ static void reds_on_main_agent_monitors_config(
+ spice_debug("not enough data yet. %d", cmc->buffer_size);
+ return;
+ }
++ if (msg_header->size < sizeof(VDAgentMonitorsConfig)) {
++ goto overflow;
++ }
+ monitors_config = (VDAgentMonitorsConfig *)(cmc->buffer + sizeof(*msg_header));
+ spice_debug("%s: %d", __func__, monitors_config->num_of_monitors);
+ red_dispatcher_client_monitors_config(monitors_config);
+--
+2.13.0
diff -Nru spice-0.12.8/debian/patches/CVE-2017-7506-3.patch spice-0.12.8/debian/patches/CVE-2017-7506-3.patch
--- spice-0.12.8/debian/patches/CVE-2017-7506-3.patch 1970-01-01 01:00:00.000000000 +0100
+++ spice-0.12.8/debian/patches/CVE-2017-7506-3.patch 2017-07-21 23:34:38.000000000 +0200
@@ -0,0 +1,46 @@
+From 8cc3d7df2792751939cc832f4110c57e2addfca5 Mon Sep 17 00:00:00 2001
+From: Frediano Ziglio <fzig...@redhat.com>
+Date: Mon, 15 May 2017 15:57:28 +0100
+Subject: [spice-server 3/3] reds: Avoid buffer overflows handling monitor
+ configuration
+
+It was also possible for a malicious client to set
+VDAgentMonitorsConfig::num_of_monitors to a number larger
+than the actual size of VDAgentMOnitorsConfig::monitors.
+This would lead to buffer overflows, which could allow the guest to
+read part of the host memory. This might cause write overflows in the
+host as well, but controlling the content of such buffers seems
+complicated.
+
+Signed-off-by: Frediano Ziglio <fzig...@redhat.com>
+---
+ server/reds.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/server/reds.c b/server/reds.c
+index e1c8c1086..3a42c3755 100644
+--- a/server/reds.c
++++ b/server/reds.c
+@@ -1000,6 +1000,7 @@ static void reds_on_main_agent_monitors_config(
+ VDAgentMessage *msg_header;
+ VDAgentMonitorsConfig *monitors_config;
+ RedsClientMonitorsConfig *cmc = &reds->client_monitors_config;
++ uint32_t max_monitors;
+
+ // limit size of message sent by the client as this can cause a DoS through
+ // memory exhaustion, or potentially some integer overflows
+@@ -1028,6 +1029,12 @@ static void reds_on_main_agent_monitors_config(
+ goto overflow;
+ }
+ monitors_config = (VDAgentMonitorsConfig *)(cmc->buffer + sizeof(*msg_header));
++ // limit the monitor number to avoid buffer overflows
++ max_monitors = (msg_header->size - sizeof(VDAgentMonitorsConfig)) /
++ sizeof(VDAgentMonConfig);
++ if (monitors_config->num_of_monitors > max_monitors) {
++ goto overflow;
++ }
+ spice_debug("%s: %d", __func__, monitors_config->num_of_monitors);
+ red_dispatcher_client_monitors_config(monitors_config);
+ reds_client_monitors_config_cleanup();
+--
+2.13.0
diff -Nru spice-0.12.8/debian/patches/series spice-0.12.8/debian/patches/series
--- spice-0.12.8/debian/patches/series 2017-02-13 21:42:01.000000000 +0100
+++ spice-0.12.8/debian/patches/series 2017-07-21 23:34:38.000000000 +0200
@@ -1,2 +1,5 @@
stop-linking-with-libcacard.diff
CVE-2016-9577-and-CVE-2016-9578.patch
+CVE-2017-7506-1.patch
+CVE-2017-7506-2.patch
+CVE-2017-7506-3.patch
