From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 790DF6B0584 for ; Wed, 9 May 2018 16:02:42 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id q15so6513325pff.17 for ; Wed, 09 May 2018 13:02:42 -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 h132-v6sor5824802pgc.390.2018.05.09.13.02.41 for (Google Transport Security); Wed, 09 May 2018 13:02:41 -0700 (PDT) From: Kees Cook Subject: [PATCH v2 6/6] device: Use overflow helpers for devm_kmalloc() Date: Wed, 9 May 2018 13:02:23 -0700 Message-Id: <20180509200223.22451-7-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 Use the overflow helpers both in existing multiplication-using inlines as well as the addition-overflow case in the core allocation routine. Signed-off-by: Kees Cook --- drivers/base/devres.c | 7 ++++++- include/linux/device.h | 8 ++++++-- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 95b67281cd2a..f98a097e73f2 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -84,9 +84,14 @@ static struct devres_group * node_to_group(struct devres_node *node) static __always_inline struct devres * alloc_dr(dr_release_t release, size_t size, gfp_t gfp, int nid) { - size_t tot_size = sizeof(struct devres) + size; + size_t tot_size; struct devres *dr; + /* We must catch any near-SIZE_MAX cases that could overflow. */ + if (unlikely(check_add_overflow(sizeof(struct devres), size, + &tot_size))) + return NULL; + dr = kmalloc_node_track_caller(tot_size, gfp, nid); if (unlikely(!dr)) return NULL; diff --git a/include/linux/device.h b/include/linux/device.h index 0059b99e1f25..e78a050d6e7e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -25,6 +25,7 @@ #include #include #include +#include #include struct device; @@ -666,9 +667,12 @@ static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp) static inline void *devm_kmalloc_array(struct device *dev, 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 devm_kmalloc(dev, n * size, flags); + + return devm_kmalloc(dev, bytes, flags); } static inline void *devm_kcalloc(struct device *dev, size_t n, size_t size, gfp_t flags) -- 2.17.0