mirror of
https://github.com/xen-project/xen.git
synced 2026-10-28 18:21:39 +01:00
Juergen Gross
268369d8e3
Today a guest is free to access as many nodes in a single transaction as it wants. This can lead to unbounded memory consumption in Xenstore as there is the need to keep track of all nodes having been accessed during a transaction. In oxenstored the number of requests in a transaction is being limited via a quota maxrequests (default is 1024). As multiple accesses of a node are not problematic in C Xenstore, limit the number of accessed nodes. In order to let read_node() detect a quota error in case too many nodes are being accessed, check the return value of access_node() and return NULL in case an error has been seen. Introduce __must_check and add it to the access_node() prototype. This is part of XSA-326 / CVE-2022-42314. Suggested-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com>