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

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From f37230c0ad481091bc136788ff8b37dc86300c6d Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Reviewed-by: Brian Paul <brianp@xxxxxxxxxx>
Reviewed-by: Sinclair Yeh <syeh@xxxxxxxxxx>

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;
 }