Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Gerd Hoffmann <kraxel@redhat.com>
To:     dri-devel@lists.freedesktop.org
Cc:     Gerd Hoffmann <kraxel@redhat.com>,
        Dave Airlie <airlied@redhat.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        virtualization@lists.linux-foundation.org (open list:DRM DRIVER FOR QXL
        VIRTUAL GPU),
        spice-devel@lists.freedesktop.org (open list:DRM DRIVER FOR QXL VIRTUAL
        GPU), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v3 23/23] drm/qxl: add overflow checks to qxl_mode_dumb_create()
Date:   Fri, 18 Jan 2019 13:20:20 +0100
Message-Id: <20190118122020.27596-24-kraxel@redhat.com>
In-Reply-To: <20190118122020.27596-1-kraxel@redhat.com>
References: <20190118122020.27596-1-kraxel@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/gpu/drm/qxl/qxl_dumb.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_dumb.c b/drivers/gpu/drm/qxl/qxl_dumb.c
index 272d19b677..bed6d06ee4 100644
--- a/drivers/gpu/drm/qxl/qxl_dumb.c
+++ b/drivers/gpu/drm/qxl/qxl_dumb.c
@@ -37,11 +37,13 @@ int qxl_mode_dumb_create(struct drm_file *file_priv,
 	uint32_t handle;
 	int r;
 	struct qxl_surface surf;
-	uint32_t pitch, format;
+	uint32_t pitch, size, format;
 
-	pitch = args->width * ((args->bpp + 1) / 8);
-	args->size = pitch * args->height;
-	args->size = ALIGN(args->size, PAGE_SIZE);
+	if (check_mul_overflow(args->width, ((args->bpp + 1) / 8), &pitch))
+		return -EINVAL;
+	if (check_mul_overflow(pitch, args->height, &size))
+		return -EINVAL;
+	args->size = ALIGN(size, PAGE_SIZE);
 
 	switch (args->bpp) {
 	case 16:
-- 
2.9.3