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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE7EBD44167 for ; Tue, 19 Nov 2024 15:17:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7DCAB6B00A1; Tue, 19 Nov 2024 10:17:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 78C8B6B00A2; Tue, 19 Nov 2024 10:17:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5DF9B6B00A3; Tue, 19 Nov 2024 10:17:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 3B1D16B00A1 for ; Tue, 19 Nov 2024 10:17:04 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id B728A805D1 for ; Tue, 19 Nov 2024 15:17:03 +0000 (UTC) X-FDA: 82803196518.16.F26D249 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf11.hostedemail.com (Postfix) with ESMTP id 9D4B840011 for ; Tue, 19 Nov 2024 15:15:57 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=MwFflXAg; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=n76FoUHD; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf11.hostedemail.com: domain of liam.howlett@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=liam.howlett@oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1732029236; a=rsa-sha256; cv=pass; b=wyJ+WmaCgA3JZp4wokZNWpvfm7YlSJlzze9Rlas30N4bKXurxPv0iuu/WYeKrKgJ7EBVPB Mfgzoay/4wE56pT0sOIJHAG6AbntUq22+yUg6bpLCO8+ahO4O8tAf+Ms5SYehWVLU1dXtJ YE8uk+5gjBFIjMbIBWOnBQwQq1+z16c= ARC-Authentication-Results: i=2; imf11.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=MwFflXAg; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=n76FoUHD; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf11.hostedemail.com: domain of liam.howlett@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=liam.howlett@oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1732029236; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ybAhFSXWvNWd0cKlxEiDnAmOoW8uMeolLQXhf2xsjLs=; b=Trnc7pWDHmz1mZFIYISlZOKOIwvXy0hKAYeet/I3879cF5USohSWBjOoRA0S+sLkrRnyau J33YF2pQ6YSVV8PVjKSimWlW3sQuTRh770AB6gN1Y6EJWQ4ei+Vgv4yXXD7uYTEzRW5SFA S0UX8ah6wsHnh+TO1Zsz5D+20YTV5vM= Received: from pps.filterd (m0333521.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4AJDhNA2001615; Tue, 19 Nov 2024 15:16:57 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2023-11-20; bh=ybAhFSXWvNWd0cKlxE iDnAmOoW8uMeolLQXhf2xsjLs=; b=MwFflXAgsELKsfDde/LclNQBBNqz+WQ4il /+3UbHM4ZHQK+Y5JWc51tSOm9BvoNCfWBJb8sGL1BErYE/qrYS+sSyv13tIykCyZ yInWcO+fuJUdwAnn0J84UCrzS57nKakYhBFMPj+kVwSjVqKScY/H8zQ/+qO2K6eL 0XUTiU5O0RPcsBIn5M7mdp67VBrcUvX//9lRRkyEYb6NtAtu1cDDHxdp7fjDe1kL KFr9oycMFHq5vKHUvHt6atNwahlmHUp95725wEHN5QSJRL3r5s/7I87cOC8ELFZr 1cNlFxRtuVarugvpOTRilGywmZEQM0qd64vSUojy36CINWy+1D6g== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 42xjaa579j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Nov 2024 15:16:56 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 4AJEB6En009019; Tue, 19 Nov 2024 15:16:56 GMT Received: from nam04-mw2-obe.outbound.protection.outlook.com (mail-mw2nam04lp2172.outbound.protection.outlook.com [104.47.73.172]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 42xhu8vdpq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Nov 2024 15:16:56 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ceuR+kpetw14tYfW+5ePw0fSIwtKrzBsDXkd7/jE9O+/yQb3VxRgZbvgU+uw74wH7pZhBcHkad1eux//vhsiCcgkQnjtGlt78wKzcNtYXWxp4Jhho2Kjn3wq18AAA2GLOdosO22QtPkjDXg6B44lJKXRlbpw27FjCMMJ3TigMCSuQv23LhJJyJ/SACDJ/xEOFB+KmLT4HBixCzP/D4AhvJljUQ++jlROHwDRc3ksfRsCh+LTbVVRDXrIhlaRHK3G2+Y7nYa2tIIe+VdX8vNtdVE7cGgWBGpkZeQp9IGfoNTlIyN3gPwcCk5blUOlHazlfPyPIOtSANARNC1Em3JNEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=ybAhFSXWvNWd0cKlxEiDnAmOoW8uMeolLQXhf2xsjLs=; b=pVMsUlXezB2qwOHef/uwiLjAK2usRDenoQ1VtlnerYekPk6Hn3UMc+SbVRn7O3dBeBh4vTJFovj14jO7sVZJzXH/nMTm+AfFRiVlgmnR1KUM63ZUSOH244myXBtYJa4I8Z2gUkpUeYAzvpzKYB0tKmZBE4mSPm644KNyEQUzj6zmdAa9u8sPgTT72wSyh3TPD+MDN1lZJIrGWsghm9eZt0mt8tfVwfYIRLA6tralcYmZuCX988+rr8FLoVj1K2N7PFoeEVNa8ZyKpcDHldwVNJbHkTtbGpWqMJGaUpzUuIPx8YImoEyaecAGvhr1JmhZeLb6ztJ2HSmfyENSgzA1Mw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ybAhFSXWvNWd0cKlxEiDnAmOoW8uMeolLQXhf2xsjLs=; b=n76FoUHDjWus9czskuSKgAe9mUA6nUTZbH2rIdYNeXhBFVH0XnPWrZ9eE2iyCfS5vQcrfpHxPA5Xv7Y0817a4ogdbQeeb8Llom7Wpw1pz84TVEf8LgE+6S7ciQt1Cur4mD+pOaVOvq8R8ZW5NKgUmnbP0opQ5tDQlB9EAS3LEg4= Received: from PH0PR10MB5777.namprd10.prod.outlook.com (2603:10b6:510:128::16) by BLAPR10MB4948.namprd10.prod.outlook.com (2603:10b6:208:307::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8158.23; Tue, 19 Nov 2024 15:16:51 +0000 Received: from PH0PR10MB5777.namprd10.prod.outlook.com ([fe80::75a8:21cc:f343:f68c]) by PH0PR10MB5777.namprd10.prod.outlook.com ([fe80::75a8:21cc:f343:f68c%6]) with mapi id 15.20.8158.021; Tue, 19 Nov 2024 15:16:51 +0000 Date: Tue, 19 Nov 2024 10:16:48 -0500 From: "Liam R. Howlett" To: Lorenzo Stoakes Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jann Horn , syzbot+bc6bfc25a68b7a020ee1@syzkaller.appspotmail.com, Vlastimil Babka , stable@vger.kernel.org Subject: Re: [PATCH 6.12.y] mm/mmap: fix __mmap_region() error handling in rare merge failure case Message-ID: Mail-Followup-To: "Liam R. Howlett" , Lorenzo Stoakes , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jann Horn , syzbot+bc6bfc25a68b7a020ee1@syzkaller.appspotmail.com, Vlastimil Babka , stable@vger.kernel.org References: <20241118194048.2355180-1-Liam.Howlett@oracle.com> <989cddf0-a3af-4f84-8b68-876e811a8795@lucifer.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <989cddf0-a3af-4f84-8b68-876e811a8795@lucifer.local> User-Agent: NeoMutt/20240425 X-ClientProxiedBy: YT4PR01CA0234.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:eb::6) To PH0PR10MB5777.namprd10.prod.outlook.com (2603:10b6:510:128::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR10MB5777:EE_|BLAPR10MB4948:EE_ X-MS-Office365-Filtering-Correlation-Id: c096a3b2-2b97-4ff2-77a9-08dd08ad31de X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?yVCIl+WuD0+3hPCcDtOcnDIp4+K/0TZPduG4LlPENw37uiSDq83bo4mqR2Ci?= =?us-ascii?Q?3FLU7Vdjto/wmAFX9+JeWwelYxPGPpRlSGL9ikTpf8JU+wXLZhr+oQqGqb2+?= =?us-ascii?Q?aArhwNydYbN80H2kcn5S7cRHW783HHSmQnHoJ9xKMAqJLNuCq+mSAb9LIIYJ?= =?us-ascii?Q?GCpr9ykA98k9hkBHukPRnaVfymmA7D32H8tyeJwU4DTNptEx8a9kA4/RBImV?= =?us-ascii?Q?aXKakryUtmMbFC9q5fa4K2klOH95OAcuz1aNOiCSzhNKBHKO7r2m9bcArjxx?= =?us-ascii?Q?k8cMM84TWS3VxC5s/wRS6jPqnv+YhDbtzj2GbrXZr33rWdY5nxUoZ4KtgjQL?= =?us-ascii?Q?E3NwCpoOUoiH9WBjCZO0Bz9Jl1jCiFCSLWqaGdVdBEnm954kVPVSWU+r2BPg?= =?us-ascii?Q?wChTvdN+m+ft7jl5RaQQu4HlrgzaumlDnBp/xljcUZvexADpZsqRk98/VrgM?= =?us-ascii?Q?SXK4qmq7dz3lsQI63eKnuF0a98JFOvyk2gV5We4aM0k0f7Y17vPQCUBfZUK+?= =?us-ascii?Q?HE3pLKMwZhuEFaqNPmRXtrf9dzVLF/f1VEZpypV8fzSg193ALxquFja2VsnZ?= =?us-ascii?Q?HKhdf+dyXbJRygT5D4p9U/VIr0ZvFAbZMmt6IVMHWo74YW6oUKvsZaBCNiY+?= =?us-ascii?Q?FvpK5B7S8NrAsnyoEgyPXSqBmODMWEmTjI8KViz/87PGcHbjAuQvactqhgkc?= =?us-ascii?Q?HVTCJvHMYd2wLKSPFaITH1NbanuOrHOJD2KMEQalO/baGAz7MAKre94h2EI3?= =?us-ascii?Q?ktn/hb1DVRxaTFcI2nVfRRA5fLU7uyfTI970gYn3HI0W/oYoFR/LbBI1NkJO?= =?us-ascii?Q?Sy1TDJU8j5pHYpjMsCUH+hvynbUMc79baGO+BZYjrvs9ZbNKnRAj1P5wEnfB?= =?us-ascii?Q?qhLbgz6XtUxGuFzgJjFEHZGVt2m5pKYUhzfLigXbX3FkL5Zlgv2C6uKA+HVC?= =?us-ascii?Q?9f1M5LL9bCVLcv3dsIAklXu+2jsPFD+5AbBs+nY169hBvqjYxTCIkiu0Lf61?= =?us-ascii?Q?i+YSKxzWdJE/lE7ijIvkVg8IrV+HUHzXPGPPKbvYy4X1zZM4thQbJ1jYcsSJ?= =?us-ascii?Q?UROZ9IyR37isGlppCtaoTRb+jPhrwLip0lB9XPeuuInVuWDgh+Yl96s+y15O?= =?us-ascii?Q?J6l9K9f1St86RcxGBKbTFY8xWIaYeiBGP+ge5pxV0D6wg2YLGYfPyW7YDtAc?= =?us-ascii?Q?Kf5WAkCoXkauppq6LxqCSa1u+Py69jjuQFQtskmktpd84qVmQTqHM+c18cH6?= =?us-ascii?Q?U/GElsg27PxiTbj4TuDR?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR10MB5777.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?sKYmKVkAKviq8t2mOzEgHUuEqHq/oi6F8+kG2bMsw4vANKYW4SuOdSmh0/+A?= =?us-ascii?Q?pV2iz+4A5+IQr0iQ09fkfW8hZ6gBouum6OuQKwP0kDLWzV44Ztb8yRK3ApTZ?= =?us-ascii?Q?hzGsIHHPyBYfcmXUq5EqYS7SKLZp3y+1NiPLr2ytOIoLarMSsRLpOVF+BzvO?= =?us-ascii?Q?g2z2hFy5VqgQWc3KwUX7KRfqMlBBq/b9h+TM09R5UJTgU5IzUaXeqNY8Lcmk?= =?us-ascii?Q?3XOPaqaEx7a5smld4SunR4ebItyjQZUdKV9+mzhb6Mn+6rhA/lLKt1YhvxEL?= =?us-ascii?Q?ULE7l4PczDIdjHx0ti6N2dToSi9dXYzRFOR+ZfpgmXBwmL5OBVYpFoJKnbLj?= =?us-ascii?Q?tgl9a4F2Ak/H+zoI8scxnI5t1OCHx0mPqVbmL50kBN+f5qecBQ7072SlJpA+?= =?us-ascii?Q?Kjce8pO+SUPc86sV2+lC175xxz9ubmzGjc5nK8OR9tVuw9AxNrnRIYXliXkD?= =?us-ascii?Q?3qBNK4+NcP6EjOUmAldayuNQXsvV6dALo2mYcO7kSRJFwTIZRqi1FcQGIBLj?= =?us-ascii?Q?1t8U99ucpyZVNA+9jdtjZR4bnaqYC9venMXJPrBKgEL0B51PQN8Jda0InBl6?= =?us-ascii?Q?v2qESi2EgVm1PkLQlhcSoq/YPmeM6YMOygx8qIe1xyj9yTU5uyBUcX3q6lqV?= =?us-ascii?Q?3pNbnYPerohZKzn/ib15P3ZlpNMjyteXQaz4pZgdZTClJVQ7Vqb24rpmF4U7?= =?us-ascii?Q?q/sqNu+KgKdl0JsWXj6VnXJVP3Qt25LqpBMhVTgus7WEHF8RTIq37xqJ3AiM?= =?us-ascii?Q?LJ5eW5v3BmxIXJ5deuG5VtnuCw1HTOCOaOE6cCIwcIOeXlbwLsUWmO1h0PAS?= =?us-ascii?Q?xeeGKlDd6l3WleNp2iI6sg6peq6suaYaJxI9ZbcHdKIWOG8SwM9DZpwhMc5o?= =?us-ascii?Q?yWbY/d8GLKoZK/ZNTjX0yxJVfCOTFaTNvMsHqLwCcLOR65kBvpvjv8lCHZzR?= =?us-ascii?Q?pRmL7JI4KLFmpDick1vr4ViBNXRNL/0cCelmIp9UvKXod0wL9+4dumuWSejk?= =?us-ascii?Q?6h71dxyG3u9yK1DH5bCOjJPNUPrutA9cUxrqccnLoedI5agPi/en4OsCX8oy?= =?us-ascii?Q?BnO8Tnkfntugws4u8g7WIUNAMVClRTm3EfIDAP2SWWPDVm0hWer5vGhZyNh6?= =?us-ascii?Q?jZi/eQwRczmy0Ask/GQU2f3UZSbTEI29WY32II15Z1q0s1dk9+h81vBmyzBQ?= =?us-ascii?Q?anTUZAi82VrVUCgDTKgozHiBHQxh/lYTpZNCI0HgQmbwD+4QSkmddKa8WFw2?= =?us-ascii?Q?SkGNOV1yl+l8jUH+bFP7XEE9NddkBXRAnIll+V+RYj9OmAI7m1arW++5syo4?= =?us-ascii?Q?pqRTnmknTKdaV9UMx+YEcE+WfLKoJmYgHPek4j1+srErClU3cJRBWUdikbh0?= =?us-ascii?Q?BL9yLLIwIqJQNVcGvPrEkONymkfLIRViyMu0c+UKLv735CHPrNeiGR6YRtbv?= =?us-ascii?Q?iat8zY3gZrXgGDEMT1Y0cWR4dciyTtuKt5yO9GB4jKdwE9fY8zovaGSP/T6z?= =?us-ascii?Q?z/86piEMddfvLZgCA2op2pdJ2zj1dyeF5bf6kDCbZbfnnlaMHd3RNg01iNKQ?= =?us-ascii?Q?+Lvk5qQB3Ys/Y6aNgN0j3bu9e8Rk1HuNulpw7GckltTOY8Fxir6+urf1RN3M?= =?us-ascii?Q?uQ=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: c096a3b2-2b97-4ff2-77a9-08dd08ad31de X-MS-Exchange-CrossTenant-AuthSource: PH0PR10MB5777.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Nov 2024 15:16:51.7717 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: f4I9scyb87oJKRlVJqRugJA45f0ilGB655JaLQdJ15cOvRPV1DlsbRdu0u076pmgBEvv/veNtcBg6r9CI9r3XA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLAPR10MB4948 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-11-19_06,2024-11-18_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 phishscore=0 suspectscore=0 adultscore=0 bulkscore=0 mlxscore=0 malwarescore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2409260000 definitions=main-2411190112 X-Proofpoint-ORIG-GUID: j5g5ntA76QT5ubaQthzpdVjYBQQ8ijs7 X-Proofpoint-GUID: j5g5ntA76QT5ubaQthzpdVjYBQQ8ijs7 X-Stat-Signature: bn3un9fgwxkwtyirmh4bmrh8yh4448j1 X-Rspamd-Queue-Id: 9D4B840011 X-Rspamd-Server: rspam08 X-Rspam-User: X-HE-Tag: 1732029357-388090 X-HE-Meta: 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 uDEatVL/ 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 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: List-Subscribe: List-Unsubscribe: * Lorenzo Stoakes [241119 09:59]: > On Mon, Nov 18, 2024 at 02:40:48PM -0500, Liam R. Howlett wrote: > > From: "Liam R. Howlett" > > > > The mmap_region() function tries to install a new vma, which requires a > > pre-allocation for the maple tree write due to the complex locking > > scenarios involved. > > > > Recent efforts to simplify the error recovery required the relocation of > > the preallocation of the maple tree nodes (via vma_iter_prealloc() > > calling mas_preallocate()) higher in the function. > > > > The relocation of the preallocation meant that, if there was a file > > associated with the vma and the driver call (mmap_file()) modified the > > vma flags, then a new merge of the new vma with existing vmas is > > attempted. > > > > During the attempt to merge the existing vma with the new vma, the vma > > iterator is used - the same iterator that would be used for the next > > write attempt to the tree. In the event of needing a further allocation > > and if the new allocations fails, the vma iterator (and contained maple > > state) will cleaned up, including freeing all previous allocations and > > will be reset internally. > > > > Upon returning to the __mmap_region() function, the error reason is lost > > and the function sets the vma iterator limits, and then tries to > > continue to store the new vma using vma_iter_store() - which expects > > preallocated nodes. > > > > A preallocation should be performed in case the allocations were lost > > during the failure scenario - there is no risk of over allocating. The > > range is already set in the vma_iter_store() call below, so it is not > > necessary. > > > > Reported-by: syzbot+bc6bfc25a68b7a020ee1@syzkaller.appspotmail.com > > Closes: https://syzkaller.appspot.com/x/log.txt?x=17b0ace8580000 > > Fixes: 5de195060b2e2 ("mm: resolve faulty mmap_region() error path behaviour") > > Signed-off-by: Liam R. Howlett > > Cc: Lorenzo Stoakes > > Cc: Vlastimil Babka > > Cc: Jann Horn > > Cc: > > --- > > mm/mmap.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/mm/mmap.c b/mm/mmap.c > > index 79d541f1502b2..5cef9a1981f1b 100644 > > --- a/mm/mmap.c > > +++ b/mm/mmap.c > > @@ -1491,7 +1491,10 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr, > > vm_flags = vma->vm_flags; > > goto file_expanded; > > } > > - vma_iter_config(&vmi, addr, end); > > + if (vma_iter_prealloc(&vmi, vma)) { > > + error = -ENOMEM; > > + goto unmap_and_free_file_vma; > > + } > > This breaks the whole thing of these changes which is to avoid having to > abort after invoking mmap_file(), so we can't do it this way. > > As discussed via IRC, it's probably best to do this with __GFP_NOFAIL or > similar to avoid the abort altogether. > > But reaching this point is very common, since drivers will often change the > flags, and failing to merge is also very common so we need to be sure this > is a no-op if no pre-allocation is required in the _very rare_ (if even > possible in reality) case of a merge failure due to OOM. The tree will do nothing if there is enough or more than needed preallocated for the operation. If this is common though, we should try to avoid the call into the tree with the vmg_nomem() test. > > We store in the vmg state whether a merge failed due to oom, which you can > test for explicitly via vmg_nomem(). Okay, I will respin. Thanks, Liam