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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Stephen Hemminger <sthemmin@microsoft.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Dexuan Cui <decui@microsoft.com>
Subject: [PATCH 4.9 41/50] Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()
Date:   Tue,  4 Dec 2018 11:50:36 +0100
Message-Id: <20181204103716.554356260@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dexuan Cui <decui@microsoft.com>

commit eceb05965489784f24bbf4d61ba60e475a983016 upstream.

This is a longstanding issue: if the vmbus upper-layer drivers try to
consume too many GPADLs, the host may return with an error
0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check
the creation_status, and hence we can pass an invalid GPADL handle
into the OPEN_CHANNEL message, and get an error code 0xc0000225 in
open_info->response.open_result.status, and finally we hang in
vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl().

With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED.

Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hv/channel.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -448,6 +448,14 @@ int vmbus_establish_gpadl(struct vmbus_c
 	}
 	wait_for_completion(&msginfo->waitevent);
 
+	if (msginfo->response.gpadl_created.creation_status != 0) {
+		pr_err("Failed to establish GPADL: err = 0x%x\n",
+		       msginfo->response.gpadl_created.creation_status);
+
+		ret = -EDQUOT;
+		goto cleanup;
+	}
+
 	if (channel->rescind) {
 		ret = -ENODEV;
 		goto cleanup;