[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 <kra...@redhat.com>

commit 34855706c30d52b0a744da44348b5d1cc39fbe51 upstream.

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

Cc: gno...@lxorguk.ukuu.org.uk
Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
Signed-off-by: Dave Airlie <airl...@redhat.com>
Signed-off-by: Luis Henriques <luis.henriq...@canonical.com>
---
 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;