From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 7A6D76B0583 for ; Wed, 9 May 2018 16:02:41 -0400 (EDT) Received: by mail-pg0-f72.google.com with SMTP id s8-v6so20028404pgf.0 for ; Wed, 09 May 2018 13:02:41 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id t25sor8179392pfj.60.2018.05.09.13.02.40 for (Google Transport Security); Wed, 09 May 2018 13:02:40 -0700 (PDT) From: Kees Cook Subject: [PATCH v2 5/6] mm: Use overflow helpers in kvmalloc() Date: Wed, 9 May 2018 13:02:22 -0700 Message-Id: <20180509200223.22451-6-keescook@chromium.org> In-Reply-To: <20180509200223.22451-1-keescook@chromium.org> References: <20180509200223.22451-1-keescook@chromium.org> Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: Kees Cook , Rasmus Villemoes , Matthew Wilcox , LKML , Linux-MM , Kernel Hardening Instead of open-coded multiplication and bounds checking, use the new overflow helper. Additionally prepare for vmalloc() users to add array_size()-family helpers in the future. Signed-off-by: Kees Cook --- include/linux/mm.h | 7 +++++-- include/linux/vmalloc.h | 1 + 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 1ac1f06a4be6..7cb1c6a6bf82 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -25,6 +25,7 @@ #include #include #include +#include struct mempolicy; struct anon_vma; @@ -560,10 +561,12 @@ static inline void *kvzalloc(size_t size, gfp_t flags) static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags) { - if (size != 0 && n > SIZE_MAX / size) + size_t bytes; + + if (unlikely(check_mul_overflow(n, size, &bytes))) return NULL; - return kvmalloc(n * size, flags); + return kvmalloc(bytes, flags); } extern void kvfree(const void *addr); diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 1e5d8c392f15..398e9c95cd61 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -8,6 +8,7 @@ #include #include /* pgprot_t */ #include +#include struct vm_area_struct; /* vma defining user mapping in mm_types.h */ struct notifier_block; /* in notifier.h */ -- 2.17.0