From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DFDAC433DF for ; Tue, 16 Jun 2020 22:54:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6799F2082F for ; Tue, 16 Jun 2020 22:54:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="XHfi2r83" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726524AbgFPWyh (ORCPT ); Tue, 16 Jun 2020 18:54:37 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:55828 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725901AbgFPWyg (ORCPT ); Tue, 16 Jun 2020 18:54:36 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05GMl5uh191571; Tue, 16 Jun 2020 22:54:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=Zmvxp6TcklTF5tZHdIjURz6zaQoJfhp55XSlQEQbRBQ=; b=XHfi2r836QGJbY2pb+IHV8UwTlHhIeA1V8Dg2/Log+JAp2Ye4WofBcW2KOqkNULm7M3H ATpM2OLgDQe5XG6K6HY7ztoLiLvIzHLuOHLH8eVNoTVPhzDyOC1lBzxjDUggJBrCyG07 G697HRQ2MY85AWBah5rFvQYT9sk/4LmdZnrSRkEcp3liTfFQ7Ooaxr7UaSb3iUQ1LFQ4 p+Tgv1PfC0OBf7Mh1KsehSwHcMheEfE9EgH5kAqhNLjJX8y/V7MU48fODynBo617Jlnu eQBNz+gPfVyWUDSLjtXNTmLG33Uc6qtFHVMerKA6Zifgs0mbRSoMU37Ba1rfiAnGelBW Ug== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 31q65jr6ye-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 16 Jun 2020 22:54:27 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05GMr54r145209; Tue, 16 Jun 2020 22:54:27 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 31q66m9sxw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Jun 2020 22:54:26 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 05GMsPkl029460; Tue, 16 Jun 2020 22:54:26 GMT Received: from localhost.localdomain (/73.243.10.6) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 16 Jun 2020 15:54:25 -0700 From: William Kucharski To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Subject: [PATCH] mm: ksize() should silently accept a NULL pointer Date: Tue, 16 Jun 2020 16:54:09 -0600 Message-Id: <20200616225409.4670-1-william.kucharski@oracle.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9654 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 adultscore=0 phishscore=0 mlxscore=0 bulkscore=0 malwarescore=0 mlxlogscore=884 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006160157 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9654 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 clxscore=1011 lowpriorityscore=0 malwarescore=0 cotscore=-2147483648 suspectscore=0 bulkscore=0 mlxlogscore=903 mlxscore=0 impostorscore=0 priorityscore=1501 phishscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006160156 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Other mm routines such as kfree() and kzfree() silently do the right thing if passed a NULL pointer, so ksize() should do the same. Signed-off-by: William Kucharski --- mm/slab_common.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 9e72ba224175..2bff01ad94d8 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1660,10 +1660,9 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size, gfp_t flags) { void *ret; - size_t ks = 0; + size_t ks; - if (p) - ks = ksize(p); + ks = ksize(p); if (ks >= new_size) { p = kasan_krealloc((void *)p, new_size, flags); @@ -1723,10 +1722,9 @@ void kzfree(const void *p) size_t ks; void *mem = (void *)p; - if (unlikely(ZERO_OR_NULL_PTR(mem))) - return; ks = ksize(mem); - memset(mem, 0, ks); + if (ks) + memset(mem, 0, ks); kfree(mem); } EXPORT_SYMBOL(kzfree); @@ -1749,8 +1747,6 @@ size_t ksize(const void *objp) { size_t size; - if (WARN_ON_ONCE(!objp)) - return 0; /* * We need to check that the pointed to object is valid, and only then * unpoison the shadow memory below. We use __kasan_check_read(), to @@ -1764,7 +1760,7 @@ size_t ksize(const void *objp) * We want to perform the check before __ksize(), to avoid potentially * crashing in __ksize() due to accessing invalid metadata. */ - if (unlikely(objp == ZERO_SIZE_PTR) || !__kasan_check_read(objp, 1)) + if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1)) return 0; size = __ksize(objp); -- 2.26.2