This is out of an abundance of caution, since this is a very basic hash function, chosen more for its bucket distribution properties to cluster related rings rather than for cryptographic strength or any uniformness of output, and it operates upon values supplied by the guest just before being used as an array index.
Signed-off-by: Christopher Clark <christopher.cla...@baesystems.com> --- xen/common/argo.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/xen/common/argo.c b/xen/common/argo.c index 39778fd..fa969ab 100644 --- a/xen/common/argo.c +++ b/xen/common/argo.c @@ -23,6 +23,7 @@ #include <xen/event.h> #include <xen/domain_page.h> #include <xen/guest_access.h> +#include <xen/nospec.h> #include <xen/time.h> #include <xsm/xsm.h> @@ -1094,7 +1095,7 @@ argo_ring_find_info(const struct domain *d, const struct argo_ring_id *id) ASSERT(rw_is_locked(&d->argo->lock)); - hash = argo_hash_fn(id); + hash = array_index_nospec(argo_hash_fn(id), ARGO_HTABLE_SIZE); argo_dprintk("d->argo=%p, d->argo->ring_hash[%d]=%p id=%p\n", d->argo, hash, d->argo->ring_hash[hash].first, id); @@ -1349,7 +1350,8 @@ argo_register_ring(struct domain *d, ring_info->id = ring.id; INIT_HLIST_HEAD(&ring_info->pending); - hash = argo_hash_fn(&ring_info->id); + hash = array_index_nospec(argo_hash_fn(&ring_info->id), + ARGO_HTABLE_SIZE); hlist_add_head(&ring_info->node, &d->argo->ring_hash[hash]); printk(XENLOG_INFO "argo: vm%u registering ring (vm%u:%x vm%d)\n", -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel