Limit relocs_num to 65536. That limit is small enougth to avoid integer overflow on 32bit machines when calculating reloc_info size (as reported by Alan Cox), and is big enougth to not block normal usage (kmalloc would ENOMEM on requests larger than that anyway).

Cc: stable@vger.kernel.org Cc: gnomes@lxorguk.ukuu.org.uk Signed-off-by: Gerd Hoffmann kraxel@redhat.com --- drivers/gpu/drm/qxl/qxl_ioctl.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c index 2ae8577..970cb83 100644 --- a/drivers/gpu/drm/qxl/qxl_ioctl.c +++ b/drivers/gpu/drm/qxl/qxl_ioctl.c @@ -168,6 +168,8 @@ static int qxl_process_single_command(struct qxl_device *qdev, cmd->command_size)) return -EFAULT;

+ if (cmd->relocs_num > 65536) + return -EINVAL; reloc_info = kmalloc(sizeof(struct qxl_reloc_info) * cmd->relocs_num, GFP_KERNEL); if (!reloc_info) return -ENOMEM;