From 500516fcb9e1c09eae9bbbd3b30bb294c6993853 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 25 Nov 2020 14:07:36 +0100 Subject: [PATCH] mm: check for truncation in vmalloc_type() While it's currently implied from the checking xmalloc_array() does, let's make this more explicit in the function itself. As a result both involved local variables don't need to have size_t type anymore. This brings them in line with the rest of the code in this file. Requested-by: Julien Grall Signed-off-by: Jan Beulich Acked-by: Julien Grall --- xen/common/vmap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/xen/common/vmap.c b/xen/common/vmap.c index faebc1ddf1..4fd6b3067e 100644 --- a/xen/common/vmap.c +++ b/xen/common/vmap.c @@ -242,13 +242,15 @@ void vunmap(const void *va) static void *vmalloc_type(size_t size, enum vmap_region type) { mfn_t *mfn; - size_t pages, i; + unsigned int i, pages = PFN_UP(size); struct page_info *pg; void *va; ASSERT(size); - pages = PFN_UP(size); + if ( PFN_DOWN(size) > pages ) + return NULL; + mfn = xmalloc_array(mfn_t, pages); if ( mfn == NULL ) return NULL; -- 2.30.2