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Peter Anvin" , Joerg Roedel , "Gustavo A . R . Silva" , Jann Horn , Srikar Dronamraju , Ricardo Neri , linux-kernel@vger.kernel.org References: <160697102582.3146288.10127018634865687932.stgit@devnote2> <160697103739.3146288.7437620795200799020.stgit@devnote2> <20201203123757.GH3059@zn.tnic> <20201203124121.GI3059@zn.tnic> <20201203124820.GJ3059@zn.tnic> <1c1b265f-34e3-f5cc-0e7b-186dc26c94b7@amd.com> <20201203165420.GL3059@zn.tnic> <20201203170140.GM3059@zn.tnic> From: Tom Lendacky Message-ID: Date: Thu, 3 Dec 2020 12:10:10 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 In-Reply-To: <20201203170140.GM3059@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [67.79.209.213] X-ClientProxiedBy: SN4PR0601CA0001.namprd06.prod.outlook.com (2603:10b6:803:2f::11) To DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from office-linux.texastahm.com (67.79.209.213) by SN4PR0601CA0001.namprd06.prod.outlook.com (2603:10b6:803:2f::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3632.17 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?WWRhQnRFNzNPMWRQYVM3RHZDNGZJck9LTmRjU2laemRpa1RvWDF6K010bnZU?= =?utf-8?B?UGV5eWlLRDZTbk1IbjIycnVybFpzbG0rWjVuN09VTkgzdGNrSFJBMzZ4RnM2?= =?utf-8?B?MzdiYm5LUlJ1UUZocDQvWktxZHpMY2U1dlFxbUxCZ3RuTlBaMXc0elJpTnpa?= =?utf-8?B?RFZ4S2x2emRoSmNsQmVxMC9yWFBKVXFoR2NSZ1B4cGFmQlYrWG02WVJPaFpX?= =?utf-8?B?OWV4dzJvbkhHaXg3a2tDRWt6Tk1Gc2tXSGRlR3pHQ1llRFFQcDRBMEx4Wmgw?= =?utf-8?B?SnRYeTAxYUNjS0QvS0xueEJiMTFjWjg3YjZUMkFYM1NLUVFHSThzeDZ4L1dG?= =?utf-8?B?eENNWGpVaFlaMUNTSEY3QWRRc2I4WmE0NDQ0SStsVmVjY09sTk4zY0hSSzh2?= =?utf-8?B?Q1hMa2VnNmxYMThwNzlBLzh6bXd3MjJJeWpBamt6VTEvZDN4UDZoejJqNUFj?= =?utf-8?B?T3R4WUs4UjJldFNPWll0OWxyODVpK0lvalVNR1NHeEdlbXRVcUNNeWdtNVN2?= =?utf-8?B?WDE3RGE4NC9jR1NqbUcvaDZpS3crcXRSbmRydWVuUmtiSlI1QTRsRDQ2Z205?= =?utf-8?B?ejJKNW53N1JOMUgxZmdjQm9BTUduMUdMdWswVHVPK2h2WndrQmVJRE1STWJz?= =?utf-8?B?d09Oc3BZdElzZ0NtVUJ1dS9kUGNCZXQ5YWRFOFZEZ0V0SVRJSmZ4Z1czSS9Q?= =?utf-8?B?UkRDTnhyZG5kOExiMDRzRGgxMitmcXFjallYSnI0ZzJXL0xDdDRPdlErOVFH?= =?utf-8?B?dEFBdnRVaTJTMEJiRzlJK3BtU2dqeE1BejRVYlI1dEZsdU5lU2p3S1U4dXlm?= =?utf-8?B?QmYzeHc5RTJMaUhTZE40V280V3dXTXNMQVF3SjB0cTRHNzFxWFg2bldJQlVh?= =?utf-8?B?MDNGMFdxcUhSZXZHOHREdFNUYmxRcXV1ZDZVbUtNZ1pHSU1DcWdRTitON1Q1?= =?utf-8?B?S3RJZHo3em9BZFBHdS9kakFxV2FNZEpNK3JueTRZN0JFUkRaMTBieXlSam5w?= =?utf-8?B?L3l4OFhTb3ZWTjY2WWZBVGdjbjJtbW5ZUlQvUDZqYnRTZkl1SHBWb1BYQ2p4?= =?utf-8?B?Sy9sRkYvdEFQMHRBc2ZtQVFJSWI2K1FKSXdCRXF1Ump6d1YyMDNpQ0paNnpi?= =?utf-8?B?R0hzemtpZHlSWUhHSXlrN1ZkRFAyTjR6bmxUM1M4alVhRythR0pkT2haWkhi?= =?utf-8?B?NmF1YnBaV2JFVmdRTnR4ekZxb1hUZW0wTnp1b3kxRFJNS0ExNG5QWm9BN2kz?= =?utf-8?B?YWgxTGRIb212blNGNmovQUFjT1AwMGRhUThnbUtaU1I5amwxcGJ5aG4way9s?= =?utf-8?Q?SQPgwKnbSpBEJaSwoDaC3+82Rao0cRhrq5?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 70a68c39-25a1-4f26-5736-08d897b6ad92 X-MS-Exchange-CrossTenant-AuthSource: DM5PR12MB1355.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Dec 2020 18:10:12.7375 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: OnzzoI2+vnyIblFpdpmvNRczQbjQrwYmevkw0RAeL8Hr7yBL+A3QIiL3CA9DSEEziBqMkRd3Y1W2O+tFEW+9oQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4958 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/3/20 11:01 AM, Borislav Petkov wrote: > On Thu, Dec 03, 2020 at 05:54:20PM +0100, Borislav Petkov wrote: >> On Thu, Dec 03, 2020 at 10:45:48AM -0600, Tom Lendacky wrote: >>> Since this is based on the array size, can >>> >>> idx < NUM_LEGACY_PREFIXES >>> >>> be replaced with: >>> >>> idx < ARRAY_SIZE(insn->prefixes.bytes) >> >> Actually, this needs another change: >> >> struct insn_field { >> union { >> insn_value_t value; >> insn_byte_t bytes[NUM_LEGACY_PREFIXES]; > > Blergh, spoke too soon. All those struct insn members are struct > insn_field. > > insn.prefixes should probably be a separate array of explicit size > NUM_LEGACY_PREFIXES, not that insn_byte_t bytes[] gets enlarged in the > future for whatever reason, while the max legacy prefixes count will > remain 4. Since that struct is used in multiple places, I think basing it on the array size is the best way to go. The main point of the check is just to be sure you don't read outside of the array. Thanks, Tom >