From patchwork Mon Jun 1 17:54:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 224932 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=-6.8 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,USER_AGENT_GIT 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 2AA37C433DF for ; Mon, 1 Jun 2020 18:50:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F093920679 for ; Mon, 1 Jun 2020 18:50:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591037435; bh=e9ONb6R08rnDyChk96rmWRWoJfzaWKahP1KGCcQT5rM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=swq2ADpMK0ruusUSHTIyGa6qB+ttHmCQa1xRMCcADJDMjoTVOOkLyUEaV9G8jztAN SFskcKzoBNmfU/no3Vfwjgi9wnRj5bktSRrO1wHmtvI7WcGQa0YFCxU4mlv3cxQz9L 0Sef/EABBTp78UkzIMMrE+HEI/vXkEWV0Fax1eBU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728937AbgFASF6 (ORCPT ); Mon, 1 Jun 2020 14:05:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:51256 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729666AbgFASF5 (ORCPT ); Mon, 1 Jun 2020 14:05:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 6AB77206E2; Mon, 1 Jun 2020 18:05:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591034756; bh=e9ONb6R08rnDyChk96rmWRWoJfzaWKahP1KGCcQT5rM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZaK1s3dfOsQWSJ+0iDdvWYflIhDBrk32dkcd4I0CVgxaB6+csPwb3RQLKt83V0VWs SEuUKS/7FRRZ/aJke+aDl0fRFJa6yq7HQTrGVJOPjEZqv46zk8mcKuAA3F3U0XR+tA 0ia4hIqCVcXuR9z9Y0VcUNaeac/P2Vm7c8fVhII4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Liviu Dudau , Andrew Morton , Chintan Pandya , Andrey Ryabinin , Linus Torvalds , Guenter Roeck Subject: [PATCH 4.19 95/95] mm/vmalloc.c: dont dereference possible NULL pointer in __vunmap() Date: Mon, 1 Jun 2020 19:54:35 +0200 Message-Id: <20200601174034.819784933@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200601174020.759151073@linuxfoundation.org> References: <20200601174020.759151073@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Liviu Dudau commit 6ade20327dbb808882888ed8ccded71e93067cf9 upstream. find_vmap_area() can return a NULL pointer and we're going to dereference it without checking it first. Use the existing find_vm_area() function which does exactly what we want and checks for the NULL pointer. Link: http://lkml.kernel.org/r/20181228171009.22269-1-liviu@dudau.co.uk Fixes: f3c01d2f3ade ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: Liviu Dudau Reviewed-by: Andrew Morton Cc: Chintan Pandya Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1510,7 +1510,7 @@ static void __vunmap(const void *addr, i addr)) return; - area = find_vmap_area((unsigned long)addr)->vm; + area = find_vm_area(addr); if (unlikely(!area)) { WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr);