qubes-linux-kernel/patches.xen/b93008d1ac65-xen-xenbus-Catch-closing-of-non-existent-transaction.patch
2018-04-16 23:21:01 +02:00

36 lines
1.3 KiB
Diff

From b93008d1ac657dc67819330c5995e65e7c3e7978 Mon Sep 17 00:00:00 2001
From: Simon Gaiser <simon@invisiblethingslab.com>
Date: Thu, 15 Mar 2018 03:43:21 +0100
Subject: [PATCH 2/3] xen: xenbus: Catch closing of non existent transactions
Users of the xenbus functions should never close a non existent
transaction (for example by trying to closing the same transaction
twice) but better catch it in xs_request_exit() than to corrupt the
reference counter.
Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
drivers/xen/xenbus/xenbus_xs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 3f3b29398ab8..49a3874ae6bb 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -140,7 +140,9 @@ void xs_request_exit(struct xb_req_data *req)
spin_lock(&xs_state_lock);
xs_state_users--;
if ((req->type == XS_TRANSACTION_START && req->msg.type == XS_ERROR) ||
- req->type == XS_TRANSACTION_END)
+ (req->type == XS_TRANSACTION_END &&
+ !WARN_ON_ONCE(req->msg.type == XS_ERROR &&
+ !strcmp(req->body, "ENOENT"))))
xs_state_users--;
spin_unlock(&xs_state_lock);
--
2.16.2