Re: FAILED: patch "[PATCH] drm/vmwgfx: Fix host logging / guestinfo reading error paths" failed to apply to 4.16-stable tree

[Thomas Hellstrom <thellstrom@vmware.com>]

Hi,

On 05/26/2018 03:10 PM, gregkh@linuxfoundation.org wrote:
> The patch below does not apply to the 4.16-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
>
> thanks,
>
> greg k-h

The IMO best option is to cherry-pick commit

6073a09210e06 "drm/vmwgfx: Use kasprintf"
by Himanshu Jha. It doesn't fix anything but is small and makes the 
below patch apply cleanly.

Thanks,
Thomas

> ------------------ original commit in Linus's tree ------------------
>
>  From f37230c0ad481091bc136788ff8b37dc86300c6d Mon Sep 17 00:00:00 2001
> From: Thomas Hellstrom <thellstrom@vmware.com>
> Date: Wed, 23 May 2018 16:13:20 +0200
> Subject: [PATCH] drm/vmwgfx: Fix host logging / guestinfo reading error paths
>
> The error paths were leaking opened channels.
> Fix by using dedicated error paths.
>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
> Reviewed-by: Brian Paul <brianp@vmware.com>
> Reviewed-by: Sinclair Yeh <syeh@vmware.com>
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> index cdff99211602..21d746bdc922 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> @@ -329,8 +329,6 @@ int vmw_host_get_guestinfo(const char *guest_info_param,
>   	struct rpc_channel channel;
>   	char *msg, *reply = NULL;
>   	size_t reply_len = 0;
> -	int ret = 0;
> -
>   
>   	if (!vmw_msg_enabled)
>   		return -ENODEV;
> @@ -344,15 +342,14 @@ int vmw_host_get_guestinfo(const char *guest_info_param,
>   		return -ENOMEM;
>   	}
>   
> -	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
> -	    vmw_send_msg(&channel, msg) ||
> -	    vmw_recv_msg(&channel, (void *) &reply, &reply_len) ||
> -	    vmw_close_channel(&channel)) {
> -		DRM_ERROR("Failed to get %s", guest_info_param);
> +	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
> +		goto out_open;
>   
> -		ret = -EINVAL;
> -	}
> +	if (vmw_send_msg(&channel, msg) ||
> +	    vmw_recv_msg(&channel, (void *) &reply, &reply_len))
> +		goto out_msg;
>   
> +	vmw_close_channel(&channel);
>   	if (buffer && reply && reply_len > 0) {
>   		/* Remove reply code, which are the first 2 characters of
>   		 * the reply
> @@ -369,7 +366,17 @@ int vmw_host_get_guestinfo(const char *guest_info_param,
>   	kfree(reply);
>   	kfree(msg);
>   
> -	return ret;
> +	return 0;
> +
> +out_msg:
> +	vmw_close_channel(&channel);
> +	kfree(reply);
> +out_open:
> +	*length = 0;
> +	kfree(msg);
> +	DRM_ERROR("Failed to get %s", guest_info_param);
> +
> +	return -EINVAL;
>   }
>   
>   
> @@ -400,15 +407,22 @@ int vmw_host_log(const char *log)
>   		return -ENOMEM;
>   	}
>   
> -	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
> -	    vmw_send_msg(&channel, msg) ||
> -	    vmw_close_channel(&channel)) {
> -		DRM_ERROR("Failed to send log\n");
> +	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
> +		goto out_open;
>   
> -		ret = -EINVAL;
> -	}
> +	if (vmw_send_msg(&channel, msg))
> +		goto out_msg;
>   
> +	vmw_close_channel(&channel);
>   	kfree(msg);
>   
> -	return ret;
> +	return 0;
> +
> +out_msg:
> +	vmw_close_channel(&channel);
> +out_open:
> +	kfree(msg);
> +	DRM_ERROR("Failed to send log\n");
> +
> +	return -EINVAL;
>   }
>