From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932439AbcE2QRT (ORCPT ); Sun, 29 May 2016 12:17:19 -0400 Received: from g4t3425.houston.hpe.com ([15.241.140.78]:38874 "EHLO g4t3425.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932323AbcE2QRS (ORCPT ); Sun, 29 May 2016 12:17:18 -0400 Date: Sun, 29 May 2016 21:47:07 +0530 From: Kuthonuzo Luruo To: aryabinin@virtuozzo.com, glider@google.com, dvyukov@google.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org Cc: kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, ynorov@caviumnetworks.com, kuthonuzo.luruo@hpe.com Subject: [PATCH v4 2/2] kasan: add double-free tests Message-ID: <20160529161707.GA5711@cherokee.in.rdlabs.hpecorp.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds new tests for KASAN double-free error detection when the same slab object is concurrently deallocated. Signed-off-by: Kuthonuzo Luruo --- Changes in v4: - There are *no* changes for v4. Changes in v3: - concurrent double-free test simplified to use on_each_cpu_mask() instead of custom threads. - reduced #threads and removed CONFIG_SMP guards per suggestion from Dmitry Vyukov. --- lib/test_kasan.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 47 insertions(+), 0 deletions(-) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 5e51872..0f589e7 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -411,6 +411,49 @@ static noinline void __init copy_user_test(void) kfree(kmem); } +#ifdef CONFIG_SLAB +static void try_free(void *p) +{ + kfree(p); +} + +static void __init kasan_double_free_concurrent(void) +{ +#define MAX_THREADS 3 + char *p; + int cpu, cnt = num_online_cpus(); + cpumask_t mask = { CPU_BITS_NONE }; + size_t size = 4097; /* must be <= KMALLOC_MAX_CACHE_SIZE/2 */ + + if (cnt == 1) + return; + cnt = cnt < MAX_THREADS ? cnt : MAX_THREADS; + pr_info("concurrent double-free (%d threads)\n", cnt); + p = kmalloc(size, GFP_KERNEL); + if (!p) + return; + for_each_online_cpu(cpu) { + cpumask_set_cpu(cpu, &mask); + if (!--cnt) + break; + } + on_each_cpu_mask(&mask, try_free, p, 0); +} + +static noinline void __init kasan_double_free(void) +{ + char *p; + size_t size = 2049; + + pr_info("double-free\n"); + p = kmalloc(size, GFP_KERNEL); + if (!p) + return; + kfree(p); + kfree(p); +} +#endif + static int __init kmalloc_tests_init(void) { kmalloc_oob_right(); @@ -436,6 +479,10 @@ static int __init kmalloc_tests_init(void) kasan_global_oob(); ksize_unpoisons_memory(); copy_user_test(); +#ifdef CONFIG_SLAB + kasan_double_free(); + kasan_double_free_concurrent(); +#endif return -EAGAIN; } -- 1.7.1