From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756105AbaG3CNw (ORCPT ); Tue, 29 Jul 2014 22:13:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60318 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754724AbaG3BtU (ORCPT ); Tue, 29 Jul 2014 21:49:20 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xi Wang , Alex Elder , David Airlie , Pekka Enberg , Andrew Morton , Linus Torvalds , Qiang Huang Subject: [PATCH 3.4 09/10] introduce SIZE_MAX Date: Tue, 29 Jul 2014 18:48:40 -0700 Message-Id: <20140730014808.019118207@linuxfoundation.org> X-Mailer: git-send-email 2.0.3 In-Reply-To: <20140730014807.477761030@linuxfoundation.org> References: <20140730014807.477761030@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Wang commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream. ULONG_MAX is often used to check for integer overflow when calculating allocation size. While ULONG_MAX happens to work on most systems, there is no guarantee that `size_t' must be the same size as `long'. This patch introduces SIZE_MAX, the maximum value of `size_t', to improve portability and readability for allocation size validation. Signed-off-by: Xi Wang Acked-by: Alex Elder Cc: David Airlie Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Qiang Huang Signed-off-by: Greg Kroah-Hartman --- fs/ceph/snap.c | 2 +- include/drm/drm_mem_util.h | 4 ++-- include/linux/kernel.h | 1 + include/linux/slab.h | 2 +- 4 files changed, 5 insertions(+), 4 deletions(-) --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -331,7 +331,7 @@ static int build_snap_context(struct cep /* alloc new snap context */ err = -ENOMEM; - if (num > (ULONG_MAX - sizeof(*snapc)) / sizeof(u64)) + if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64)) goto fail; snapc = kzalloc(sizeof(*snapc) + num*sizeof(u64), GFP_NOFS); if (!snapc) --- a/include/drm/drm_mem_util.h +++ b/include/drm/drm_mem_util.h @@ -31,7 +31,7 @@ static __inline__ void *drm_calloc_large(size_t nmemb, size_t size) { - if (size != 0 && nmemb > ULONG_MAX / size) + if (size != 0 && nmemb > SIZE_MAX / size) return NULL; if (size * nmemb <= PAGE_SIZE) @@ -44,7 +44,7 @@ static __inline__ void *drm_calloc_large /* Modeled after cairo's malloc_ab, it's like calloc but without the zeroing. */ static __inline__ void *drm_malloc_ab(size_t nmemb, size_t size) { - if (size != 0 && nmemb > ULONG_MAX / size) + if (size != 0 && nmemb > SIZE_MAX / size) return NULL; if (size * nmemb <= PAGE_SIZE) --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -35,6 +35,7 @@ #define LLONG_MAX ((long long)(~0ULL>>1)) #define LLONG_MIN (-LLONG_MAX - 1) #define ULLONG_MAX (~0ULL) +#define SIZE_MAX (~(size_t)0) #define STACK_MAGIC 0xdeadbeef --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -242,7 +242,7 @@ size_t ksize(const void *); */ static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) { - if (size != 0 && n > ULONG_MAX / size) + if (size != 0 && n > SIZE_MAX / size) return NULL; return __kmalloc(n * size, flags); }