[SRU][Cosmic][PATCH 1/2] Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()

[Joseph Salisbury]

From: Dexuan Cui <decui at microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/1807757

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 at microsoft.com>
Cc: K. Y. Srinivasan <kys at microsoft.com>
Cc: Haiyang Zhang <haiyangz at microsoft.com>
Cc: stable at vger.kernel.org
Signed-off-by: Dexuan Cui <decui at microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit eceb05965489784f24bbf4d61ba60e475a983016)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 drivers/hv/channel.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index c394922..5898669 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -469,6 +469,14 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	}
 	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;
-- 
2.7.4