Messages in this thread Patch in this message | | | From | Simon Gaiser <> | Subject | [PATCH v2 3/3] xen: xenbus_dev_frontend: Verify body of XS_TRANSACTION_END | Date | Thu, 15 Mar 2018 03:43:22 +0100 |
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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 <simon@invisiblethingslab.com> --- 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
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