From 8fe5ab411209ac6e2c7021131e622fd004506d1a Mon Sep 17 00:00:00 2001 From: Simon Gaiser Date: Thu, 15 Mar 2018 03:43:22 +0100 Subject: [PATCH 3/3] xen: xenbus_dev_frontend: Verify body of XS_TRANSACTION_END By guaranteeing that the argument of XS_TRANSACTION_END is valid we can assume that the transaction has been closed when we get an XS_ERROR response from xenstore (Note that we already verify that it's a valid transaction id). Signed-off-by: Simon Gaiser Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky --- drivers/xen/xenbus/xenbus_dev_frontend.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index 81a84b3c1c50..0d6d9264d6a9 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -429,6 +429,10 @@ static int xenbus_write_transaction(unsigned msg_type, { int rc; struct xenbus_transaction_holder *trans = NULL; + struct { + struct xsd_sockmsg hdr; + char body[]; + } *msg = (void *)u->u.buffer; if (msg_type == XS_TRANSACTION_START) { trans = kzalloc(sizeof(*trans), GFP_KERNEL); @@ -437,11 +441,15 @@ static int xenbus_write_transaction(unsigned msg_type, goto out; } list_add(&trans->list, &u->transactions); - } else if (u->u.msg.tx_id != 0 && - !xenbus_get_transaction(u, u->u.msg.tx_id)) + } else if (msg->hdr.tx_id != 0 && + !xenbus_get_transaction(u, msg->hdr.tx_id)) return xenbus_command_reply(u, XS_ERROR, "ENOENT"); + else if (msg_type == XS_TRANSACTION_END && + !(msg->hdr.len == 2 && + (!strcmp(msg->body, "T") || !strcmp(msg->body, "F")))) + return xenbus_command_reply(u, XS_ERROR, "EINVAL"); - rc = xenbus_dev_request_and_reply(&u->u.msg, u); + rc = xenbus_dev_request_and_reply(&msg->hdr, u); if (rc && trans) { list_del(&trans->list); kfree(trans); -- 2.16.2