From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id D13696B026A for ; Thu, 31 May 2018 20:43:49 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id t5-v6so5789587pgt.18 for ; Thu, 31 May 2018 17:43:49 -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 a129-v6sor14769668pfb.146.2018.05.31.17.43.48 for (Google Transport Security); Thu, 31 May 2018 17:43:48 -0700 (PDT) From: Kees Cook Subject: [PATCH v3 07/16] mm: Use overflow helpers in kvmalloc() Date: Thu, 31 May 2018 17:42:24 -0700 Message-Id: <20180601004233.37822-8-keescook@chromium.org> In-Reply-To: <20180601004233.37822-1-keescook@chromium.org> References: <20180601004233.37822-1-keescook@chromium.org> Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: Kees Cook , Linus Torvalds , 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