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From: "Jan Beulich" <JBeulich@suse.com>
To: <david.vrabel@citrix.com>, <boris.ostrovsky@oracle.com>,
	"Juergen Gross" <JGross@suse.com>
Cc: <xen-devel@lists.xenproject.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] xenbus: don't BUG() on user mode induced condition
Date: Thu, 07 Jul 2016 01:23:57 -0600	[thread overview]
Message-ID: <577E1FAD02000078000FBD88@prv-mh.provo.novell.com> (raw)

Inability to locate a user mode specified transaction ID should not
lead to a kernel crash. For other than XS_TRANSACTION_START also
don't issue anything to xenbus if the specified ID doesn't match that
of any active transaction.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
 drivers/xen/xenbus/xenbus_dev_frontend.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

--- 4.7-rc6-xen.orig/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ 4.7-rc6-xen/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -316,11 +316,18 @@ static int xenbus_write_transaction(unsi
 			rc = -ENOMEM;
 			goto out;
 		}
+	} else {
+		list_for_each_entry(trans, &u->transactions, list)
+			if (trans->handle.id == u->u.msg.tx_id)
+				break;
+		if (&trans->list == &u->transactions)
+			return -ESRCH;
 	}
 
 	reply = xenbus_dev_request_and_reply(&u->u.msg);
 	if (IS_ERR(reply)) {
-		kfree(trans);
+		if (msg_type == XS_TRANSACTION_START)
+			kfree(trans);
 		rc = PTR_ERR(reply);
 		goto out;
 	}
@@ -333,12 +340,7 @@ static int xenbus_write_transaction(unsi
 			list_add(&trans->list, &u->transactions);
 		}
 	} else if (u->u.msg.type == XS_TRANSACTION_END) {
-		list_for_each_entry(trans, &u->transactions, list)
-			if (trans->handle.id == u->u.msg.tx_id)
-				break;
-		BUG_ON(&trans->list == &u->transactions);
 		list_del(&trans->list);
-
 		kfree(trans);
 	}
 

WARNING: multiple messages have this Message-ID (diff)
From: "Jan Beulich" <JBeulich@suse.com>
To: david.vrabel@citrix.com, boris.ostrovsky@oracle.com,
	Juergen Gross <JGross@suse.com>
Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org
Subject: [PATCH] xenbus: don't BUG() on user mode induced condition
Date: Thu, 07 Jul 2016 01:23:57 -0600	[thread overview]
Message-ID: <577E1FAD02000078000FBD88@prv-mh.provo.novell.com> (raw)

Inability to locate a user mode specified transaction ID should not
lead to a kernel crash. For other than XS_TRANSACTION_START also
don't issue anything to xenbus if the specified ID doesn't match that
of any active transaction.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
 drivers/xen/xenbus/xenbus_dev_frontend.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

--- 4.7-rc6-xen.orig/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ 4.7-rc6-xen/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -316,11 +316,18 @@ static int xenbus_write_transaction(unsi
 			rc = -ENOMEM;
 			goto out;
 		}
+	} else {
+		list_for_each_entry(trans, &u->transactions, list)
+			if (trans->handle.id == u->u.msg.tx_id)
+				break;
+		if (&trans->list == &u->transactions)
+			return -ESRCH;
 	}
 
 	reply = xenbus_dev_request_and_reply(&u->u.msg);
 	if (IS_ERR(reply)) {
-		kfree(trans);
+		if (msg_type == XS_TRANSACTION_START)
+			kfree(trans);
 		rc = PTR_ERR(reply);
 		goto out;
 	}
@@ -333,12 +340,7 @@ static int xenbus_write_transaction(unsi
 			list_add(&trans->list, &u->transactions);
 		}
 	} else if (u->u.msg.type == XS_TRANSACTION_END) {
-		list_for_each_entry(trans, &u->transactions, list)
-			if (trans->handle.id == u->u.msg.tx_id)
-				break;
-		BUG_ON(&trans->list == &u->transactions);
 		list_del(&trans->list);
-
 		kfree(trans);
 	}
 




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             reply	other threads:[~2016-07-07  7:25 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-07  7:23 Jan Beulich [this message]
2016-07-07  7:23 ` [PATCH] xenbus: don't BUG() on user mode induced condition Jan Beulich
2016-07-07 11:21 ` David Vrabel
2016-07-07 11:21 ` [Xen-devel] " David Vrabel
2016-08-21 19:36 ` Sylvain Munaut
2016-08-21 19:36 ` [Xen-devel] " Sylvain Munaut
2016-08-21 20:00   ` Christoph Moench-Tegeder
2016-08-21 21:18     ` Sylvain Munaut
2016-08-22  6:45   ` [Xen-devel] " Jan Beulich
2016-08-22  7:21     ` Sylvain Munaut
2016-08-22  7:21     ` [Xen-devel] " Sylvain Munaut
2016-08-22  6:45   ` Jan Beulich

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