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authorJuergen Gross <jgross@suse.com>2016-12-22 08:19:46 +0100
committerJuergen Gross <jgross@suse.com>2016-12-23 20:06:20 +0100
commit639b08810d6ad74ded2c5f6e233c4fcb9d147168 (patch)
treed34974d8c4278fdbf88d8fa3ab755d04d615b856 /drivers
parentxen/evtchn: use rb_entry() (diff)
downloadlinux-639b08810d6ad74ded2c5f6e233c4fcb9d147168.tar.xz
linux-639b08810d6ad74ded2c5f6e233c4fcb9d147168.zip
xen: xenbus driver must not accept invalid transaction ids
When accessing Xenstore in a transaction the user is specifying a transaction id which he normally obtained from Xenstore when starting the transaction. Xenstore is validating a transaction id against all known transaction ids of the connection the request came in. As all requests of a domain not being the one where Xenstore lives share one connection, validation of transaction ids of different users of Xenstore in that domain should be done by the kernel of that domain being the multiplexer between the Xenstore users in that domain and Xenstore. In order to prohibit one Xenstore user "hijacking" a transaction from another user the xenbus driver has to verify a given transaction id against all known transaction ids of the user before forwarding it to Xenstore. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/xen/xenbus/xenbus_dev_frontend.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 6c0ead4be784..a06828124b70 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -316,7 +316,7 @@ static int xenbus_write_transaction(unsigned msg_type,
rc = -ENOMEM;
goto out;
}
- } else if (msg_type == XS_TRANSACTION_END) {
+ } else if (u->u.msg.tx_id != 0) {
list_for_each_entry(trans, &u->transactions, list)
if (trans->handle.id == u->u.msg.tx_id)
break;