Prevent out-of-range register accesses.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
                printk(KERN_ERR "Unable to ioremap cafe-ccic regs\n");
                goto out_disable;
        }
+       mcam->regs_size = pci_resource_len(pdev, 0);
        ret = request_irq(pdev->irq, cafe_irq, IRQF_SHARED, "cafe-ccic", cam);
        if (ret)
                goto out_iounmap;
 
 {
        struct mcam_camera *cam = priv;
 
+       if (reg->reg > cam->regs_size - 4)
+               return -EINVAL;
        reg->val = mcam_reg_read(cam, reg->reg);
        reg->size = 4;
        return 0;
 {
        struct mcam_camera *cam = priv;
 
+       if (reg->reg > cam->regs_size - 4)
+               return -EINVAL;
        mcam_reg_write(cam, reg->reg, reg->val);
        return 0;
 }
 
         */
        struct i2c_adapter *i2c_adapter;
        unsigned char __iomem *regs;
+       unsigned regs_size; /* size in bytes of the register space */
        spinlock_t dev_lock;
        struct device *dev; /* For messages, dma alloc */
        enum mcam_chip_id chip_id;
 
                ret = -ENODEV;
                goto out_free;
        }
+       mcam->regs_size = resource_size(res);
        /*
         * Power/clock memory is elsewhere; get it too.  Perhaps this
         * should really be managed outside of this driver?