From: Juergen Gross jgross@suse.com
Commit b0576cc9c6b843d99c6982888d59a56209341888 upstream.
Instead of __get_free_pages() and free_pages() use alloc_pages_exact() and free_pages_exact(). This is in preparation of a change of gnttab_end_foreign_access() which will prohibit use of high-order pages.
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser simon@invisiblethingslab.com Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Jan Beulich jbeulich@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/pvcalls-front.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -346,8 +346,8 @@ static void free_active_ring(struct sock if (!map->active.ring) return;
- free_pages((unsigned long)map->active.data.in, - map->active.ring->ring_order); + free_pages_exact(map->active.data.in, + PAGE_SIZE << map->active.ring->ring_order); free_page((unsigned long)map->active.ring); }
@@ -361,8 +361,8 @@ static int alloc_active_ring(struct sock goto out;
map->active.ring->ring_order = PVCALLS_RING_ORDER; - bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, - PVCALLS_RING_ORDER); + bytes = alloc_pages_exact(PAGE_SIZE << PVCALLS_RING_ORDER, + GFP_KERNEL | __GFP_ZERO); if (!bytes) goto out;