From ac90823eccd05943a2ece5f7a8a9892d0c44e2a7 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Mon, 5 Dec 2022 15:32:55 -0500 Subject: [PATCH 4/6] hw/display/qxl: Pass requested buffer size to qxl_phys2virt() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jon Maloy 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 RH-Acked-by: Marc-André Lureau RH-Acked-by: Stefan Hajnoczi 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 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 Acked-by: Gerd Hoffmann Signed-off-by: Stefan Hajnoczi Message-Id: <20221128202741.4945-4-philmd@linaro.org> (cherry picked from commit 8efec0ef8bbc1e75a7ebf6e325a35806ece9b39f) Signed-off-by: Jon Maloy --- 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