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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 9D959C43610 for ; Thu, 29 Nov 2018 14:25:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65FB1205C9 for ; Thu, 29 Nov 2018 14:25:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="F+LWGbDT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65FB1205C9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732892AbeK3Bao (ORCPT ); Thu, 29 Nov 2018 20:30:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:57894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731565AbeK3Ban (ORCPT ); Thu, 29 Nov 2018 20:30:43 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 871DD205C9; Thu, 29 Nov 2018 14:25:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543501511; bh=glyMymXp4qZVOxjvHuWhLfftmhm9G1Q6Z2kkfzoglXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F+LWGbDTTsl0c/M4Z8gD9Ji69KsDCSj/8gqQptahy6Pld7DE1/O3LnNVn2GNEF+Ae yXlj/xDv6g7DS0wHP6qtAFkzCTIEYUFI3yrX+0IrhRe3xoZ1FXVC9n8SOPwGfPHIOe gfnDpygmV6l8LISSWD3qotJQv8ChtvVO+81TF0FI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , syzbot+87829a10073277282ad1@syzkaller.appspotmail.com, syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com, syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com, syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com, syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com, Christoph Lameter , Vlastimil Babka , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 028/100] mm: dont warn about large allocations for slab Date: Thu, 29 Nov 2018 15:11:58 +0100 Message-Id: <20181129140101.148133119@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181129140058.768942700@linuxfoundation.org> References: <20181129140058.768942700@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Vyukov commit 61448479a9f2c954cde0cfe778cb6bec5d0a748d upstream. Slub does not call kmalloc_slab() for sizes > KMALLOC_MAX_CACHE_SIZE, instead it falls back to kmalloc_large(). For slab KMALLOC_MAX_CACHE_SIZE == KMALLOC_MAX_SIZE and it calls kmalloc_slab() for all allocations relying on NULL return value for over-sized allocations. This inconsistency leads to unwanted warnings from kmalloc_slab() for over-sized allocations for slab. Returning NULL for failed allocations is the expected behavior. Make slub and slab code consistent by checking size > KMALLOC_MAX_CACHE_SIZE in slab before calling kmalloc_slab(). While we are here also fix the check in kmalloc_slab(). We should check against KMALLOC_MAX_CACHE_SIZE rather than KMALLOC_MAX_SIZE. It all kinda worked because for slab the constants are the same, and slub always checks the size against KMALLOC_MAX_CACHE_SIZE before kmalloc_slab(). But if we get there with size > KMALLOC_MAX_CACHE_SIZE anyhow bad things will happen. For example, in case of a newly introduced bug in slub code. Also move the check in kmalloc_slab() from function entry to the size > 192 case. This partially compensates for the additional check in slab code and makes slub code a bit faster (at least theoretically). Also drop __GFP_NOWARN in the warning check. This warning means a bug in slab code itself, user-passed flags have nothing to do with it. Nothing of this affects slob. Link: http://lkml.kernel.org/r/20180927171502.226522-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov Reported-by: syzbot+87829a10073277282ad1@syzkaller.appspotmail.com Reported-by: syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com Reported-by: syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com Reported-by: syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com Reported-by: syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com Acked-by: Christoph Lameter Acked-by: Vlastimil Babka Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/slab.c | 4 ++++ mm/slab_common.c | 12 ++++++------ 2 files changed, 10 insertions(+), 6 deletions(-) --- a/mm/slab.c +++ b/mm/slab.c @@ -3670,6 +3670,8 @@ __do_kmalloc_node(size_t size, gfp_t fla struct kmem_cache *cachep; void *ret; + if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) + return NULL; cachep = kmalloc_slab(size, flags); if (unlikely(ZERO_OR_NULL_PTR(cachep))) return cachep; @@ -3705,6 +3707,8 @@ static __always_inline void *__do_kmallo struct kmem_cache *cachep; void *ret; + if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) + return NULL; cachep = kmalloc_slab(size, flags); if (unlikely(ZERO_OR_NULL_PTR(cachep))) return cachep; --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -971,18 +971,18 @@ struct kmem_cache *kmalloc_slab(size_t s { int index; - if (unlikely(size > KMALLOC_MAX_SIZE)) { - WARN_ON_ONCE(!(flags & __GFP_NOWARN)); - return NULL; - } - if (size <= 192) { if (!size) return ZERO_SIZE_PTR; index = size_index[size_index_elem(size)]; - } else + } else { + if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) { + WARN_ON(1); + return NULL; + } index = fls(size - 1); + } #ifdef CONFIG_ZONE_DMA if (unlikely((flags & GFP_DMA)))