[pve-devel] [PATCH pve-libspice-server] Add fix for CVE-2019-3813

[Dominik Csapak]

Fix comes from oss-security at lists.openwall.com
changed g_critical to spice_critical so that the patch applies

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
 Makefile                                           |   2 +-
 debian/changelog                                   |   6 ++
 ...-off-by-one-error-in-group-slot-boundary-.patch | 102 +++++++++++++++++++++
 debian/patches/series                              |   1 +
 4 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 debian/patches/0001-memslot-Fix-off-by-one-error-in-group-slot-boundary-.patch

diff --git a/Makefile b/Makefile
index 54f2bfa..92b953d 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ RELEASE=4.0
 
 PACKAGE=pve-libspice-server1
 PKGVERSION=0.14.1
-PKGRELEASE=1
+PKGRELEASE=2
 
 PKGDIR=spice-${PKGVERSION}
 PKGSRC=${PKGDIR}.tar.bz2
diff --git a/debian/changelog b/debian/changelog
index a987473..bbb370b 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+pve-libspice-server (0.14.1-2) unstable; urgency=medium
+
+  * Fix CVE-2019-3813
+
+ -- Promxox Support Team <support at proxmox.com>  Tue, 29 Jan 2019 09:46:41 +0100
+
 pve-libspice-server (0.14.1-1) unstable; urgency=medium
 
   * upgrade to 0.14.1
diff --git a/debian/patches/0001-memslot-Fix-off-by-one-error-in-group-slot-boundary-.patch b/debian/patches/0001-memslot-Fix-off-by-one-error-in-group-slot-boundary-.patch
new file mode 100644
index 0000000..30aed66
--- /dev/null
+++ b/debian/patches/0001-memslot-Fix-off-by-one-error-in-group-slot-boundary-.patch
@@ -0,0 +1,102 @@
+From 6eff47e72cb2f23d168be58bab8bdd60df49afd0 Mon Sep 17 00:00:00 2001
+From: Christophe Fergeau <cfergeau at redhat.com>
+Date: Thu, 29 Nov 2018 14:18:39 +0100
+Subject: [spice-server] memslot: Fix off-by-one error in group/slot boundary
+ check
+
+RedMemSlotInfo keeps an array of groups, and each group contains an
+array of slots. Unfortunately, these checks are off by 1, they check
+that the index is greater or equal to the number of elements in the
+array, while these arrays are 0 based. The check should only check for
+strictly greater than the number of elements.
+
+For the group array, this is not a big issue, as these memslot groups
+are created by spice-server users (eg QEMU), and the group ids used to
+index that array are also generated by the spice-server user, so it
+should not be possible for the guest to set them to arbitrary values.
+
+The slot id is more problematic, as it's calculated from a QXLPHYSICAL
+address, and such addresses are usually set by the guest QXL driver, so
+the guest can set these to arbitrary values, including malicious values,
+which are probably easy to build from the guest PCI configuration.
+
+This patch fixes the arrays bound check, and adds a test case for this.
+
+Signed-off-by: Christophe Fergeau <cfergeau at redhat.com>
+Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
+---
+ server/memslot.c                |  4 ++--
+ server/tests/test-qxl-parsing.c | 30 ++++++++++++++++++++++++++++++
+ 2 files changed, 32 insertions(+), 2 deletions(-)
+
+diff --git a/server/memslot.c b/server/memslot.c
+index b27324efb..fb3d5cfd5 100644
+--- a/server/memslot.c
++++ b/server/memslot.c
+@@ -97,13 +97,13 @@ void *memslot_get_virt(RedMemSlotInfo *info, QXLPHYSICAL addr, uint32_t add_size
+ 
+     MemSlot *slot;
+ 
+-    if (group_id > info->num_memslots_groups) {
++    if (group_id >= info->num_memslots_groups) {
+         spice_critical("group_id too big");
+         return NULL;
+     }
+ 
+     slot_id = memslot_get_id(info, addr);
+-    if (slot_id > info->num_memslots) {
++    if (slot_id >= info->num_memslots) {
+         print_memslots(info);
+         spice_critical("slot_id %d too big, addr=%" PRIx64, slot_id, addr);
+         return NULL;
+diff --git a/server/tests/test-qxl-parsing.c b/server/tests/test-qxl-parsing.c
+index 8565239f0..447425984 100644
+--- a/server/tests/test-qxl-parsing.c
++++ b/server/tests/test-qxl-parsing.c
+@@ -98,6 +98,31 @@ static void deinit_qxl_surface(QXLSurfaceCmd *qxl)
+     g_free(from_physical(qxl->u.surface_create.data));
+ }
+ 
++static void test_memslot_invalid_group_id(void)
++{
++    RedMemSlotInfo mem_info;
++    init_meminfo(&mem_info);
++
++    memslot_get_virt(&mem_info, 0, 16, 1);
++}
++
++static void test_memslot_invalid_slot_id(void)
++{
++    RedMemSlotInfo mem_info;
++    init_meminfo(&mem_info);
++
++    memslot_get_virt(&mem_info, 1 << mem_info.memslot_id_shift, 16, 0);
++}
++
++static void test_memslot_invalid_addresses(void)
++{
++    g_test_trap_subprocess("/server/memslot-invalid-addresses/subprocess/group_id", 0, 0);
++    g_test_trap_assert_stderr("*group_id too big*");
++
++    g_test_trap_subprocess("/server/memslot-invalid-addresses/subprocess/slot_id", 0, 0);
++    g_test_trap_assert_stderr("*slot_id 1 too big*");
++}
++
+ static void test_no_issues(void)
+ {
+     RedMemSlotInfo mem_info;
+@@ -317,6 +342,11 @@ int main(int argc, char *argv[])
+ {
+     g_test_init(&argc, &argv, NULL);
+ 
++    /* try to use invalid memslot group/slot */
++    g_test_add_func("/server/memslot-invalid-addresses", test_memslot_invalid_addresses);
++    g_test_add_func("/server/memslot-invalid-addresses/subprocess/group_id", test_memslot_invalid_group_id);
++    g_test_add_func("/server/memslot-invalid-addresses/subprocess/slot_id", test_memslot_invalid_slot_id);
++
+     /* try to create a surface with no issues, should succeed */
+     g_test_add_func("/server/qxl-parsing-no-issues", test_no_issues);
+ 
+-- 
+2.19.2
+
diff --git a/debian/patches/series b/debian/patches/series
index 247f05d..ab02eda 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1 +1,2 @@
 allow-to-set-sasl-callbacks.patch
+0001-memslot-Fix-off-by-one-error-in-group-slot-boundary-.patch
-- 
2.11.0