From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by kanga.kvack.org (Postfix) with ESMTP id 833D58E0002 for ; Wed, 2 Jan 2019 10:51:13 -0500 (EST) Received: by mail-qt1-f197.google.com with SMTP id w19so39495958qto.13 for ; Wed, 02 Jan 2019 07:51:13 -0800 (PST) Received: from a9-31.smtp-out.amazonses.com (a9-31.smtp-out.amazonses.com. [54.240.9.31]) by mx.google.com with ESMTPS id a24si624776qvd.18.2019.01.02.07.51.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 02 Jan 2019 07:51:12 -0800 (PST) Date: Wed, 2 Jan 2019 15:51:12 +0000 From: Christopher Lameter Subject: Re: BUG: unable to handle kernel NULL pointer dereference in setup_kmem_cache_node In-Reply-To: Message-ID: <010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com> References: <0000000000000f35c6057e780d36@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dmitry Vyukov Cc: syzbot , Dominique Martinet , David Miller , Eric Van Hensbergen , LKML , Latchesar Ionkov , netdev , syzkaller-bugs , v9fs-developer@lists.sourceforge.net, Linux-MM , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton On Wed, 2 Jan 2019, Dmitry Vyukov wrote: > Am I missing something or __alloc_alien_cache misses check for > kmalloc_node result? > > static struct alien_cache *__alloc_alien_cache(int node, int entries, > int batch, gfp_t gfp) > { > size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); > struct alien_cache *alc = NULL; > > alc = kmalloc_node(memsize, gfp, node); > init_arraycache(&alc->ac, entries, batch); > spin_lock_init(&alc->lock); > return alc; > } > True _alloc_alien_cache() needs to check for NULL From: Christoph Lameter Subject: slab: Alien caches must not be initialized if the allocation of the alien cache failed Callers of __alloc_alien() check for NULL. We must do the same check in __alloc_alien_cache to avoid NULL pointer dereferences on allocation failures. Signed-off-by: Christoph Lameter Index: linux/mm/slab.c =================================================================== --- linux.orig/mm/slab.c +++ linux/mm/slab.c @@ -666,8 +666,10 @@ static struct alien_cache *__alloc_alien struct alien_cache *alc = NULL; alc = kmalloc_node(memsize, gfp, node); - init_arraycache(&alc->ac, entries, batch); - spin_lock_init(&alc->lock); + if (alc) { + init_arraycache(&alc->ac, entries, batch); + spin_lock_init(&alc->lock); + } return alc; } 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=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 81461C43387 for ; Wed, 2 Jan 2019 15:51:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 36FC6218DE for ; Wed, 2 Jan 2019 15:51:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazonses.com header.i=@amazonses.com header.b="E+ay9z6r" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36FC6218DE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C31308E0027; Wed, 2 Jan 2019 10:51:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BE0148E0002; Wed, 2 Jan 2019 10:51:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD19D8E0027; Wed, 2 Jan 2019 10:51:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by kanga.kvack.org (Postfix) with ESMTP id 833D58E0002 for ; Wed, 2 Jan 2019 10:51:13 -0500 (EST) Received: by mail-qt1-f197.google.com with SMTP id w19so39495958qto.13 for ; Wed, 02 Jan 2019 07:51:13 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :in-reply-to:message-id:references:user-agent:mime-version :feedback-id; bh=rEkE6Caj2p88PSsCUc8oU/jhCd4SVEFpbmMGCBsImRk=; b=a6TDzzhZvgxumA1s9qg8s2lxfyabYp6snToGPCWkBdeI+GjvffaL4UndVpx4TO3z6s sDLfjHS7jBylA3C3VXw8faBLVzwuoIoxC+R/AyTKov2Nockc7kObU+ioDzoy6xqBfm7B bAfe5KR3mmjRRJCGYIUWfHsLr7twDF1dmJWi9EyZFJZ5KsyXTjkv6vmiuMe873M+acXa TsulARw/6TSJzgCJDdPjHmDc+uKGDZsq2earLuXjH8Yfp6fmEiJz4Vy+5emQTEKMh9+G p2EOnM9BRDBRQtzX9EK6fmsYSio/Kh7Yh5RFNevCwsvRSfWj62E/7fXXY0SartrioWit SUIQ== X-Gm-Message-State: AJcUukf2eiuNtfhTismJL3/Z1AzljScNoT3gbHbv8wKVqJwI0mIfyU3U zzAyeJW+59MLJlshF6sAl2a2QDc2iovuQbl05THZeyo3r1Bbum3K8PX7YE1HRgDhKaxKZrP6i43 D9sCLwPYlsci4fN6g9ZZq6cpPI0ioVMJLf2FCavHFA4e4YpAuSIWCA22yTx/CpsY= X-Received: by 2002:a0c:cc8c:: with SMTP id f12mr43502430qvl.102.1546444273255; Wed, 02 Jan 2019 07:51:13 -0800 (PST) X-Google-Smtp-Source: ALg8bN6KcU/ZdhoZMAonm0TVGKpzMcxT+ABrd5bM4QZcQKQADGKFoaTya1odR+60n0oObAhp5MLa X-Received: by 2002:a0c:cc8c:: with SMTP id f12mr43502400qvl.102.1546444272685; Wed, 02 Jan 2019 07:51:12 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1546444272; cv=none; d=google.com; s=arc-20160816; b=QB+Sa2JR0qyM2mtDKJcX26oAgCRgxcfp48YNYVYF1hnUMewUlCbFls1WiqRj7lGgzL w4LkDMaEAoZu5JTp6GazbniryMYikAfDSWHdn/vEmxbfmbrfz/eC+jBm5XbToywOKAAV /NP+vRULf3SBwJfWoWSU1qthqAm497WyO8AZfVtlqs5dxtEo/xjT9LgYVzrnSii6PtZi xgCjbRpAjtCDI8SRAi/kwFoxFfY0AP5kvqvRbCT/5Omcpe7XAgADyy3fUvOwWJ590AFG U7j3ZveqigsK/f77DMcvLDA0QzxVg1zIi1BtVNX+TSwsaFYCOfmTnXQw86uHRSMa+cUF eXjQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=feedback-id:mime-version:user-agent:references:message-id :in-reply-to:subject:cc:to:from:date:dkim-signature; bh=rEkE6Caj2p88PSsCUc8oU/jhCd4SVEFpbmMGCBsImRk=; b=xDxu533f3AL7Sbcf+waX8VZH2/1Xr4mWyr4SPA3i1JBEgmo3HuTmMqgLKYe+SILqcZ v8qmb83U4n9SUByA1H+QiFvmI1lnbcB3YNkPj2DmjhYgpqV4lX36GYTnxPot1vLM5nVk ZfayvL+6cBFXLuXgVa69o7hBB6nFGmIfWLXwwBlVBylFgJSGlBDEiP6u/ssZngc8gdl1 YpcbeUGCWs0Lz3t8HviXsoKpdRr0EKWEzi7CZc+pU9jUnApFy5DlnyGQHx21azvvVQzu R++yASBumFuPW+6vTQTlObbzdUp1rn1JhfBZ8gAmOR0mBRZkFk+V0ArCNv9i/re7DH0P pNjw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@amazonses.com header.s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug header.b=E+ay9z6r; spf=pass (google.com: domain of 010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@amazonses.com designates 54.240.9.31 as permitted sender) smtp.mailfrom=010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@amazonses.com Received: from a9-31.smtp-out.amazonses.com (a9-31.smtp-out.amazonses.com. [54.240.9.31]) by mx.google.com with ESMTPS id a24si624776qvd.18.2019.01.02.07.51.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 02 Jan 2019 07:51:12 -0800 (PST) Received-SPF: pass (google.com: domain of 010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@amazonses.com designates 54.240.9.31 as permitted sender) client-ip=54.240.9.31; Authentication-Results: mx.google.com; dkim=pass header.i=@amazonses.com header.s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug header.b=E+ay9z6r; spf=pass (google.com: domain of 010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@amazonses.com designates 54.240.9.31 as permitted sender) smtp.mailfrom=010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@amazonses.com DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug; d=amazonses.com; t=1546444272; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:MIME-Version:Content-Type:Feedback-ID; bh=QrUfP2uIZHKXzgqGsLcs1smTdC8d+WI0qnJh55aBLBQ=; b=E+ay9z6r2ElMB3D6TaKMceeFTQChZVSdJ/tI015jziOWfgTHqD8pIvknKXq8bhCO OzAN+3av/7KCiiN5Ms+prXwen9ym67IxOnCFTJDogUhCVKdgPN6nSpFyCZSNbUWeVxF wQl+HZo6yvoqyQx5pu0jR4MFs4/N5YaPY/Rfulac= Date: Wed, 2 Jan 2019 15:51:12 +0000 From: Christopher Lameter X-X-Sender: cl@nuc-kabylake To: Dmitry Vyukov cc: syzbot , Dominique Martinet , David Miller , Eric Van Hensbergen , LKML , Latchesar Ionkov , netdev , syzkaller-bugs , v9fs-developer@lists.sourceforge.net, Linux-MM , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Subject: Re: BUG: unable to handle kernel NULL pointer dereference in setup_kmem_cache_node In-Reply-To: Message-ID: <010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com> References: <0000000000000f35c6057e780d36@google.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-SES-Outgoing: 2019.01.02-54.240.9.31 Feedback-ID: 1.us-east-1.fQZZZ0Xtj2+TD7V5apTT/NrT6QKuPgzCT/IC7XYgDKI=:AmazonSES X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Message-ID: <20190102155112.tTiD6jWYgIkFqQYfLUCV2SfvUIqHGxw7lJmT7HpusYM@z> On Wed, 2 Jan 2019, Dmitry Vyukov wrote: > Am I missing something or __alloc_alien_cache misses check for > kmalloc_node result? > > static struct alien_cache *__alloc_alien_cache(int node, int entries, > int batch, gfp_t gfp) > { > size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); > struct alien_cache *alc = NULL; > > alc = kmalloc_node(memsize, gfp, node); > init_arraycache(&alc->ac, entries, batch); > spin_lock_init(&alc->lock); > return alc; > } > True _alloc_alien_cache() needs to check for NULL From: Christoph Lameter Subject: slab: Alien caches must not be initialized if the allocation of the alien cache failed Callers of __alloc_alien() check for NULL. We must do the same check in __alloc_alien_cache to avoid NULL pointer dereferences on allocation failures. Signed-off-by: Christoph Lameter Index: linux/mm/slab.c =================================================================== --- linux.orig/mm/slab.c +++ linux/mm/slab.c @@ -666,8 +666,10 @@ static struct alien_cache *__alloc_alien struct alien_cache *alc = NULL; alc = kmalloc_node(memsize, gfp, node); - init_arraycache(&alc->ac, entries, batch); - spin_lock_init(&alc->lock); + if (alc) { + init_arraycache(&alc->ac, entries, batch); + spin_lock_init(&alc->lock); + } return alc; }