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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 2ACA2C33CB2 for ; Fri, 31 Jan 2020 06:15:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D703A20663 for ; Fri, 31 Jan 2020 06:15:14 +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 D703A20663 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) Received: by kanga.kvack.org (Postfix, from userid 40) id 3C28E6B0551; Fri, 31 Jan 2020 01:15:09 -0500 (EST) 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-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-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: _