From d89ce52096982d2b5ff3f81f9dc0c8316590fe41 Mon Sep 17 00:00:00 2001 From: Leo Famulari Date: Wed, 12 Jul 2017 15:39:34 -0400 Subject: gnu: spice: Fix CVE-2017-7506. * gnu/packages/patches/spice-CVE-2017-7506.patch: New file. * gnu/local.mk (dist_patch_DATA): Add it. * gnu/packages/spice.scm (spice)[source]: Use it. --- gnu/local.mk | 1 + gnu/packages/patches/spice-CVE-2017-7506.patch | 158 +++++++++++++++++++++++++ gnu/packages/spice.scm | 3 +- 3 files changed, 161 insertions(+), 1 deletion(-) create mode 100644 gnu/packages/patches/spice-CVE-2017-7506.patch (limited to 'gnu') diff --git a/gnu/local.mk b/gnu/local.mk index 199792b4f3..4da9cba27d 100644 --- a/gnu/local.mk +++ b/gnu/local.mk @@ -1006,6 +1006,7 @@ dist_patch_DATA = \ %D%/packages/patches/spice-CVE-2016-9577.patch \ %D%/packages/patches/spice-CVE-2016-9578-1.patch \ %D%/packages/patches/spice-CVE-2016-9578-2.patch \ + %D%/packages/patches/spice-CVE-2017-7506.patch \ %D%/packages/patches/steghide-fixes.patch \ %D%/packages/patches/superlu-dist-scotchmetis.patch \ %D%/packages/patches/swish-e-search.patch \ diff --git a/gnu/packages/patches/spice-CVE-2017-7506.patch b/gnu/packages/patches/spice-CVE-2017-7506.patch new file mode 100644 index 0000000000..37d8f02831 --- /dev/null +++ b/gnu/packages/patches/spice-CVE-2017-7506.patch @@ -0,0 +1,158 @@ +Fix CVE-2017-7506: + +https://bugzilla.redhat.com/show_bug.cgi?id=1452606 +https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7506 + +Patches copied from Debian spice package version +'spice_0.12.8-2.1+deb9u1.debian.tar.xz': +http://security.debian.org/debian-security/pool/updates/main/s/spice/spice_0.12.8-2.1+deb9u1.debian.tar.xz + +The patches had to be adapted to apply to the latest spice tarball, and +are based on these upstream commits: + +https://cgit.freedesktop.org/spice/spice/commit/?id=111ab38611cef5012f1565a65fa2d8a8a05cce37 +https://cgit.freedesktop.org/spice/spice/commit/?id=571cec91e71c2aae0d5f439ea2d8439d0c3d75eb +https://cgit.freedesktop.org/spice/spice/commit/?id=fbbcdad773e2791cfb988f4748faa41943551ca6 + +From 257f69d619fed407493156c8a7b952abc8a51314 Mon Sep 17 00:00:00 2001 +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. + +--- + 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 +From ff2b4ef70181087d5abd50bad76d026ec5088a93 Mon Sep 17 00:00:00 2001 +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. + +--- + 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 +From 8cc3d7df2792751939cc832f4110c57e2addfca5 Mon Sep 17 00:00:00 2001 +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. + +--- + 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 --git a/gnu/packages/spice.scm b/gnu/packages/spice.scm index 08343c52ed..8baf4f4a6d 100644 --- a/gnu/packages/spice.scm +++ b/gnu/packages/spice.scm @@ -211,7 +211,8 @@ which allows users to view a desktop computing environment.") (base32 "0za03i77j8i3g5l2np2j7vy8cqsdbkm9wbv4hjnaqq9xhz2sa0gr")) (patches - (search-patches "spice-CVE-2016-9577.patch" + (search-patches "spice-CVE-2017-7506.patch" + "spice-CVE-2016-9577.patch" "spice-CVE-2016-9578-1.patch" "spice-CVE-2016-9578-2.patch")))) (build-system gnu-build-system) -- cgit v1.2.3