From ac90823eccd05943a2ece5f7a8a9892d0c44e2a7 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Mon, 5 Dec 2022 15:32:55 -0500
Subject: [PATCH 4/6] hw/display/qxl: Pass requested buffer size to
qxl_phys2virt()
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RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 242: hw/display/qxl: Have qxl_log_command Return early if no log_cmd handler
RH-Bugzilla: 2152085
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Commit: [3/5] 89de533fc1f5cc142cfa0ffd213d8683d009ac54 (jmaloy/jons-qemu-kvm)
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=2152085
CVE: CVE-2022-4144
Upstream: Merged
commit 8efec0ef8bbc1e75a7ebf6e325a35806ece9b39f
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date: Mon Nov 28 21:27:39 2022 +0100
hw/display/qxl: Pass requested buffer size to qxl_phys2virt()
Currently qxl_phys2virt() doesn't check for buffer overrun.
In order to do so in the next commit, pass the buffer size
as argument.
For QXLCursor in qxl_render_cursor() -> qxl_cursor() we
verify the size of the chunked data ahead, checking we can
access 'sizeof(QXLCursor) + chunk->data_size' bytes.
Since in the SPICE_CURSOR_TYPE_MONO case the cursor is
assumed to fit in one chunk, no change are required.
In SPICE_CURSOR_TYPE_ALPHA the ahead read is handled in
qxl_unpack_chunks().
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221128202741.4945-4-philmd@linaro.org>
(cherry picked from commit 8efec0ef8bbc1e75a7ebf6e325a35806ece9b39f)
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
hw/display/qxl-logger.c | 11 ++++++++---
hw/display/qxl-render.c | 20 ++++++++++++++++----
hw/display/qxl.c | 14 +++++++++-----
hw/display/qxl.h | 4 +++-
4 files changed, 36 insertions(+), 13 deletions(-)
diff --git a/hw/display/qxl-logger.c b/hw/display/qxl-logger.c
index 1bcf803db6..35c38f6252 100644
--- a/hw/display/qxl-logger.c
+++ b/hw/display/qxl-logger.c
@@ -106,7 +106,7 @@ static int qxl_log_image(PCIQXLDevice *qxl, QXLPHYSICAL addr, int group_id)
QXLImage *image;
QXLImageDescriptor *desc;
- image = qxl_phys2virt(qxl, addr, group_id);
+ image = qxl_phys2virt(qxl, addr, group_id, sizeof(QXLImage));
if (!image) {
return 1;
}
@@ -214,7 +214,8 @@ int qxl_log_cmd_cursor(PCIQXLDevice *qxl, QXLCursorCmd *cmd, int group_id)
cmd->u.set.position.y,
cmd->u.set.visible ? "yes" : "no",
cmd->u.set.shape);
- cursor = qxl_phys2virt(qxl, cmd->u.set.shape, group_id);
+ cursor = qxl_phys2virt(qxl, cmd->u.set.shape, group_id,
+ sizeof(QXLCursor));
if (!cursor) {
return 1;
}
@@ -236,6 +237,7 @@ int qxl_log_command(PCIQXLDevice *qxl, const char *ring, QXLCommandExt *ext)
{
bool compat = ext->flags & QXL_COMMAND_FLAG_COMPAT;
void *data;
+ size_t datasz;
int ret;
if (!qxl->cmdlog) {
@@ -249,15 +251,18 @@ int qxl_log_command(PCIQXLDevice *qxl, const char *ring, QXLCommandExt *ext)
switch (ext->cmd.type) {
case QXL_CMD_DRAW:
+ datasz = compat ? sizeof(QXLCompatDrawable) : sizeof(QXLDrawable);
break;
case QXL_CMD_SURFACE:
+ datasz = sizeof(QXLSurfaceCmd);
break;
case QXL_CMD_CURSOR:
+ datasz = sizeof(QXLCursorCmd);
break;
default:
goto out;
}
- data = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id);
+ data = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id, datasz);
if (!data) {
return 1;
}
diff --git a/hw/display/qxl-render.c b/hw/display/qxl-render.c
index ca217004bf..fcfd40c3ac 100644
--- a/hw/display/qxl-render.c
+++ b/hw/display/qxl-render.c
@@ -107,7 +107,9 @@ static void qxl_render_update_area_unlocked(PCIQXLDevice *qxl)
qxl->guest_primary.resized = 0;
qxl->guest_primary.data = qxl_phys2virt(qxl,
qxl->guest_primary.surface.mem,
- MEMSLOT_GROUP_GUEST);
+ MEMSLOT_GROUP_GUEST,
+ qxl->guest_primary.abs_stride
+ * height);
if (!qxl->guest_primary.data) {
goto end;
}
@@ -228,7 +230,8 @@ static void qxl_unpack_chunks(void *dest, size_t size, PCIQXLDevice *qxl,
if (offset == size) {
return;
}
- chunk = qxl_phys2virt(qxl, chunk->next_chunk, group_id);
+ chunk = qxl_phys2virt(qxl, chunk->next_chunk, group_id,
+ sizeof(QXLDataChunk) + chunk->data_size);
if (!chunk) {
return;
}
@@ -295,7 +298,8 @@ fail:
/* called from spice server thread context only */
int qxl_render_cursor(PCIQXLDevice *qxl, QXLCommandExt *ext)
{
- QXLCursorCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id);
+ QXLCursorCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id,
+ sizeof(QXLCursorCmd));
QXLCursor *cursor;
QEMUCursor *c;
@@ -314,7 +318,15 @@ int qxl_render_cursor(PCIQXLDevice *qxl, QXLCommandExt *ext)
}
switch (cmd->type) {
case QXL_CURSOR_SET:
- cursor = qxl_phys2virt(qxl, cmd->u.set.shape, ext->group_id);
+ /* First read the QXLCursor to get QXLDataChunk::data_size ... */
+ cursor = qxl_phys2virt(qxl, cmd->u.set.shape, ext->group_id,
+ sizeof(QXLCursor));
+ if (!cursor) {
+ return 1;
+ }
+ /* Then read including the chunked data following QXLCursor. */
+ cursor = qxl_phys2virt(qxl, cmd->u.set.shape, ext->group_id,
+ sizeof(QXLCursor) + cursor->chunk.data_size);
if (!cursor) {
return 1;
}
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 29c80b4289..aa9065183e 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -274,7 +274,8 @@ static void qxl_spice_monitors_config_async(PCIQXLDevice *qxl, int replay)
QXL_IO_MONITORS_CONFIG_ASYNC));
}
- cfg = qxl_phys2virt(qxl, qxl->guest_monitors_config, MEMSLOT_GROUP_GUEST);
+ cfg = qxl_phys2virt(qxl, qxl->guest_monitors_config, MEMSLOT_GROUP_GUEST,
+ sizeof(QXLMonitorsConfig));
if (cfg != NULL && cfg->count == 1) {
qxl->guest_primary.resized = 1;
qxl->guest_head0_width = cfg->heads[0].width;
@@ -459,7 +460,8 @@ static int qxl_track_command(PCIQXLDevice *qxl, struct QXLCommandExt *ext)
switch (le32_to_cpu(ext->cmd.type)) {
case QXL_CMD_SURFACE:
{
- QXLSurfaceCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id);
+ QXLSurfaceCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id,
+ sizeof(QXLSurfaceCmd));
if (!cmd) {
return 1;
@@ -494,7 +496,8 @@ static int qxl_track_command(PCIQXLDevice *qxl, struct QXLCommandExt *ext)
}
case QXL_CMD_CURSOR:
{
- QXLCursorCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id);
+ QXLCursorCmd *cmd = qxl_phys2virt(qxl, ext->cmd.data, ext->group_id,
+ sizeof(QXLCursorCmd));
if (!cmd) {
return 1;
@@ -1444,7 +1447,8 @@ static bool qxl_get_check_slot_offset(PCIQXLDevice *qxl, QXLPHYSICAL pqxl,
}
/* can be also called from spice server thread context */
-void *qxl_phys2virt(PCIQXLDevice *qxl, QXLPHYSICAL pqxl, int group_id)
+void *qxl_phys2virt(PCIQXLDevice *qxl, QXLPHYSICAL pqxl, int group_id,
+ size_t size)
{
uint64_t offset;
uint32_t slot;
@@ -1952,7 +1956,7 @@ static void qxl_dirty_surfaces(PCIQXLDevice *qxl)
}
cmd = qxl_phys2virt(qxl, qxl->guest_surfaces.cmds[i],
- MEMSLOT_GROUP_GUEST);
+ MEMSLOT_GROUP_GUEST, sizeof(QXLSurfaceCmd));
assert(cmd);
assert(cmd->type == QXL_SURFACE_CMD_CREATE);
qxl_dirty_one_surface(qxl, cmd->u.surface_create.data,
diff --git a/hw/display/qxl.h b/hw/display/qxl.h
index c938f88a2f..c784315daa 100644
--- a/hw/display/qxl.h
+++ b/hw/display/qxl.h
@@ -153,6 +153,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(PCIQXLDevice, PCI_QXL)
* @qxl: QXL device
* @phys: physical offset of buffer within the VRAM
* @group_id: memory slot group
+ * @size: size of the buffer
*
* Returns a host pointer to a buffer placed at offset @phys within the
* active slot @group_id of the PCI VGA RAM memory region associated with
@@ -166,7 +167,8 @@ OBJECT_DECLARE_SIMPLE_TYPE(PCIQXLDevice, PCI_QXL)
* the incoming ram_addr_t.
*
*/
-void *qxl_phys2virt(PCIQXLDevice *qxl, QXLPHYSICAL phys, int group_id);
+void *qxl_phys2virt(PCIQXLDevice *qxl, QXLPHYSICAL phys, int group_id,
+ size_t size);
void qxl_set_guest_bug(PCIQXLDevice *qxl, const char *msg, ...)
GCC_FMT_ATTR(2, 3);
--
2.37.3