From patchwork Fri Jan 31 06:15:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11359273 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7E226139A for ; Fri, 31 Jan 2020 06:15:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4BA7120663 for ; Fri, 31 Jan 2020 06:15:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xpkgMl1E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BA7120663 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 45D096B054F; Fri, 31 Jan 2020 01:15:09 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3C28E6B0551; Fri, 31 Jan 2020 01:15:09 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23B636B0552; Fri, 31 Jan 2020 01:15:09 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 05D546B054F for ; Fri, 31 Jan 2020 01:15:09 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9D7234DAE for ; Fri, 31 Jan 2020 06:15:08 +0000 (UTC) X-FDA: 76436916696.25.pig91_2ce13ae04ee16 X-Spam-Summary: 2,0,0,169139562ec8304e,d41d8cd98f00b204,akpm@linux-foundation.org,:akpm@linux-foundation.org:dan.carpenter@oracle.com::mm-commits@vger.kernel.org:torvalds@linux-foundation.org:vitaly.wool@konsulko.com,RULES_HIT:41:355:379:800:960:967:968:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3870:3871:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4250:4321:5007:6261:6653:7576:8599:9025:9545:10004:10913:11026:11473:11658:11914:12043:12048:12297:12438:12517:12519:12555:12679:12783:12986:13069:13153:13161:13228:13229:13311:13357:14094:14181:14384:14721:14849:21080:21451:21611:21627:21939:21990:30054:30064,0,RBL:error,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: pig91_2ce13ae04ee16 X-Filterd-Recvd-Size: 2520 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 31 Jan 2020 06:15:08 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 805612173E; Fri, 31 Jan 2020 06:15:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580451307; bh=TRUrpRLatAiBNPo/qocX7mzRykPN+XaM0nhUqw0uzj4=; h=Date:From:To:Subject:In-Reply-To:From; b=xpkgMl1EIMe0YzmNSQYy9Z6jplNdV3f1P3cK14TzleuAFid/cBtDXJx8EEiYepLin Q2dQjm8OnMY8kRZlH0LiZ3gq7WtcRLKtPMRekk0uya41cXLX1ea8jhoHedwiIWOsw6 GJ+BcDuCRbapG8DnjtHfB58RvayAsGk6m2I9viSk= Date: Thu, 30 Jan 2020 22:15:07 -0800 From: Andrew Morton To: akpm@linux-foundation.org, dan.carpenter@oracle.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vitaly.wool@konsulko.com Subject: [patch 074/118] zswap: potential NULL dereference on error in init_zswap() Message-ID: <20200131061507.Ird0gLXRR%akpm@linux-foundation.org> In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Dan Carpenter Subject: zswap: potential NULL dereference on error in init_zswap() The "pool" pointer can be NULL at the end of the init_zswap(). (We would allocate a new pool later in that situation.) So in the error handling then we need to make sure pool is a valid pointer before calling "zswap_pool_destroy(pool);" because that function dereferences the argument. Link: http://lkml.kernel.org/r/20200114050902.og32fkllkod5ycf5@kili.mountain Fixes: 93d4dfa9fbd0 ("mm/zswap.c: add allocation hysteresis if pool limit is hit") Signed-off-by: Dan Carpenter Cc: Vitaly Wool Signed-off-by: Andrew Morton --- mm/zswap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/zswap.c~zswap-potential-null-dereference-on-error-in-init_zswap +++ a/mm/zswap.c @@ -1359,7 +1359,8 @@ static int __init init_zswap(void) return 0; fallback_fail: - zswap_pool_destroy(pool); + if (pool) + zswap_pool_destroy(pool); hp_fail: cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE); dstmem_fail: