[PATCH 3.16.y-ckt 021/142] drm/qxl: use kmalloc_array to alloc reloc_info in qxl_process_single_command

[Luis Henriques]

3.16.7-ckt26 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Gerd Hoffmann <kraxel@xxxxxxxxxx>

commit 34855706c30d52b0a744da44348b5d1cc39fbe51 upstream.

This avoids integer overflows on 32bit machines when calculating
reloc_info size, as reported by Alan Cox.

Cc: gnomes@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/qxl/qxl_ioctl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c
index 7354a4cda59d..3aefaa058f0c 100644
--- a/drivers/gpu/drm/qxl/qxl_ioctl.c
+++ b/drivers/gpu/drm/qxl/qxl_ioctl.c
@@ -168,7 +168,8 @@ static int qxl_process_single_command(struct qxl_device *qdev,
 		       cmd->command_size))
 		return -EFAULT;
 
-	reloc_info = kmalloc(sizeof(struct qxl_reloc_info) * cmd->relocs_num, GFP_KERNEL);
+	reloc_info = kmalloc_array(cmd->relocs_num,
+				   sizeof(struct qxl_reloc_info), GFP_KERNEL);
 	if (!reloc_info)
 		return -ENOMEM;