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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 3E6A0C433E1 for ; Wed, 12 Aug 2020 01:31:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 04865206B2 for ; Wed, 12 Aug 2020 01:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Myn4mVib" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04865206B2 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 9DE088D000A; Tue, 11 Aug 2020 21:31:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 96B448D0001; Tue, 11 Aug 2020 21:31:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7C24D8D000A; Tue, 11 Aug 2020 21:31:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id 5EAC88D0001 for ; Tue, 11 Aug 2020 21:31:56 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2990A180AD811 for ; Wed, 12 Aug 2020 01:31:56 +0000 (UTC) X-FDA: 77140190232.29.work95_5b1091726fe7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 0093F18086E34 for ; Wed, 12 Aug 2020 01:31:55 +0000 (UTC) X-HE-Tag: work95_5b1091726fe7 X-Filterd-Recvd-Size: 2414 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 12 Aug 2020 01:31:55 +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 AA0802076C; Wed, 12 Aug 2020 01:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597195915; bh=T7Tmm8z8t+ocoM26YhmOhdhVWRVA5H+gc57af3leT7o=; h=Date:From:To:Subject:In-Reply-To:From; b=Myn4mVibv2vidXjEnjH0yDLJZeP0z4lMrZ4ZCxFNN1a4ek3mQjWRytfsrJNVIusd2 jthGXippMYxKXPGDzBlhc0z4qtSlyIPpFtKAyUJWYuSr475rRNfUIwDNomr5Bh+i2K 8gif2N5y8kk8xLlnZbN/yRpGipviSl78Fy9SEVhA= Date: Tue, 11 Aug 2020 18:31:54 -0700 From: Andrew Morton To: akpm@linux-foundation.org, david@redhat.com, jay.xu@rock-chips.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 031/165] mm/cma.c: fix NULL pointer dereference when cma could not be activated Message-ID: <20200812013154.RGm-7uVDJ%akpm@linux-foundation.org> In-Reply-To: <20200811182949.e12ae9a472e3b5e27e16ad6c@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 0093F18086E34 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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: Jianqun Xu Subject: mm/cma.c: fix NULL pointer dereference when cma could not be activated In some case the cma area could not be activated, but the cma_alloc be used under this case, then the kernel will crash caused by NULL pointer dereference. Add bitmap valid check in cma_alloc to avoid this issue. Link: http://lkml.kernel.org/r/20200615010123.15596-1-jay.xu@rock-chips.com Signed-off-by: Jianqun Xu Reviewed-by: David Hildenbrand Signed-off-by: Andrew Morton --- mm/cma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/cma.c~mm-cma-fix-null-pointer-dereference-when-cma-could-not-be-activated +++ a/mm/cma.c @@ -425,7 +425,7 @@ struct page *cma_alloc(struct cma *cma, struct page *page = NULL; int ret = -ENOMEM; - if (!cma || !cma->count) + if (!cma || !cma->count || !cma->bitmap) return NULL; pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma, _