diff options
Diffstat (limited to 'main/spice/CVE-2019-3813.patch')
-rw-r--r-- | main/spice/CVE-2019-3813.patch | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/main/spice/CVE-2019-3813.patch b/main/spice/CVE-2019-3813.patch new file mode 100644 index 0000000000..1f80c1eb60 --- /dev/null +++ b/main/spice/CVE-2019-3813.patch @@ -0,0 +1,102 @@ +From 6eff47e72cb2f23d168be58bab8bdd60df49afd0 Mon Sep 17 00:00:00 2001 +From: Christophe Fergeau <cfergeau@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@redhat.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 ede77e7..ea6f981 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 + + |