linux-kernel - [PATCH 1/1] Drivers: hv: vmbus: Don't leak memory when a channel is rescinded

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Message-Id: <1489374030-29806-1-git-send-email-kys@exchange.microsoft.com>
Date:   Sun, 12 Mar 2017 20:00:30 -0700
From:   kys@...hange.microsoft.com
To:     gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
        devel@...uxdriverproject.org, olaf@...fle.de, apw@...onical.com,
        vkuznets@...hat.com, jasowang@...hat.com,
        leann.ogasawara@...onical.com, marcelo.cerri@...onical.com
Cc:     "K. Y. Srinivasan" <kys@...rosoft.com>
Subject: [PATCH 1/1] Drivers: hv: vmbus: Don't leak memory when a channel is rescinded

From: K. Y. Srinivasan <kys@...rosoft.com>

When we close a channel that has been rescinded, we will leak memory since
vmbus_teardown_gpadl() returns an error. Fix this so that we can properly
cleanup the memory allocated to the ring buffers.

Fixes: ccb61f8a99e6 ("Drivers: hv: vmbus: Fix a rescind handling bug")

Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
---
 drivers/hv/channel.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 54075ac..e9b0fab 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -502,12 +502,15 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 
 	wait_for_completion(&info->waitevent);
 
-	if (channel->rescind) {
-		ret = -ENODEV;
-		goto post_msg_err;
-	}
-
 post_msg_err:
+	/*
+	 * If the channel has been rescinded;
+	 * we will be awakened by the rescind
+	 * handler; set the error code to zero so we don't leak memory.
+	 */
+	if (channel->rescind)
+		ret = 0;
+
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&info->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-- 
1.7.1