* Re: [PATCH] udlfb: fix some inconsistent NULL checking
2018-10-10 10:36 ` [PATCH] udlfb: fix some inconsistent NULL checking Dan Carpenter
@ 2018-12-20 15:34 ` Bartlomiej Zolnierkiewicz
0 siblings, 0 replies; 2+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2018-12-20 15:34 UTC (permalink / raw)
To: Dan Carpenter
Cc: linux-fbdev, kernel-janitors, Bernie Thompson, dri-devel,
Mikulas Patocka, Colin Ian King, Wen Yang, Alexey Khoroshilov
[ added Mikulas, Alexey, Colin & Wen to Cc: ]
On 10/10/2018 12:36 PM, Dan Carpenter wrote:
> In the current kernel, then kzalloc() can't fail for small allocations,
> but if it did fail then we would have a NULL dereference in the error
> handling. Also in dlfb_usb_disconnect() if "info" were NULL then it
> would cause an Oops inside the unregister_framebuffer() function but it
> can't be NULL so let's remove that check.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Patch queued for 4.21, thanks (also sorry for the delay).
[ Mikulas, Alexey, Colin & Wen: please verify that there are no known
issues with udlfb left with this patch applied (thanks!). ]
> diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
> index 070026a7e55a..1d034dddc556 100644
> --- a/drivers/video/fbdev/udlfb.c
> +++ b/drivers/video/fbdev/udlfb.c
> @@ -1598,7 +1598,7 @@ static int dlfb_usb_probe(struct usb_interface *intf,
> dlfb = kzalloc(sizeof(*dlfb), GFP_KERNEL);
> if (!dlfb) {
> dev_err(&intf->dev, "%s: failed to allocate dlfb\n", __func__);
> - goto error;
> + return -ENOMEM;
> }
>
> INIT_LIST_HEAD(&dlfb->deferred_free);
> @@ -1703,7 +1703,7 @@ static int dlfb_usb_probe(struct usb_interface *intf,
> error:
> if (dlfb->info) {
> dlfb_ops_destroy(dlfb->info);
> - } else if (dlfb) {
> + } else {
> usb_put_dev(dlfb->udev);
> kfree(dlfb);
> }
> @@ -1730,12 +1730,10 @@ static void dlfb_usb_disconnect(struct usb_interface *intf)
> /* this function will wait for all in-flight urbs to complete */
> dlfb_free_urb_list(dlfb);
>
> - if (info) {
> - /* remove udlfb's sysfs interfaces */
> - for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
> - device_remove_file(info->dev, &fb_device_attrs[i]);
> - device_remove_bin_file(info->dev, &edid_attr);
> - }
> + /* remove udlfb's sysfs interfaces */
> + for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
> + device_remove_file(info->dev, &fb_device_attrs[i]);
> + device_remove_bin_file(info->dev, &edid_attr);
>
> unregister_framebuffer(info);
> }
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
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