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To: YANG LI , CC: , , , , , , , , , , , References: <1608793298-123684-1-git-send-email-abaci-bugfix@linux.alibaba.com> From: Yonghong Song Message-ID: Date: Wed, 23 Dec 2020 23:31:58 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 In-Reply-To: <1608793298-123684-1-git-send-email-abaci-bugfix@linux.alibaba.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [2620:10d:c090:400::5:20ab] X-ClientProxiedBy: CO2PR04CA0139.namprd04.prod.outlook.com (2603:10b6:104::17) To BYAPR15MB4088.namprd15.prod.outlook.com (2603:10b6:a02:c3::18) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [IPv6:2620:10d:c085:21c1::135f] (2620:10d:c090:400::5:20ab) by CO2PR04CA0139.namprd04.prod.outlook.com (2603:10b6:104::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3700.27 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?TFBmcFQrZ2lHbC9ybjlMR3FNcjNWbjVMZ0hpMjBmK0VqS3NuZFdmeHo2WmNi?= =?utf-8?B?NGlDM1JpcVZVbmsya2oxZlBSbVlXd2hGYWN0aGlld3ZVcVZodEdVMHVlYytX?= =?utf-8?B?L0ZzcDF6ZWlIOFBUWlFYK2w2NW9nbk9oKzdPQzdEWjRYQ0hlU2lWZ016QzZs?= =?utf-8?B?NklUU0wvcVE5cGh2RC8yd1FWb0FoQ09vT0thM0VKWmlPNHhtR3NCSm9NWWtl?= =?utf-8?B?ZThydjQ2RUMrM0lSZW1PM3FUM0pxaXZsVTYwbTRNYklwLzZ6S3VMZGVNeUdU?= =?utf-8?B?WkVDNFNpK1FINlN3YUVVeC9WV0hpQmhoS0x3NUlKeWdGYXJZVVNkOElLZmtv?= =?utf-8?B?RjU1ZnZMZGxhOW9yYUxyZ0hVcUg1U3FZNVkvUzNRaENHQk9HbitMRGxFRjFM?= =?utf-8?B?M0djcmErdTVJM0RvZUV3VmdVbHlxc2IrUHBHZzlwblVCWlZ5bFk4QWl1Q3lG?= =?utf-8?B?VDRYdThMRy9xWDJkN0dZajg4eVRQbTZ6TmxqK01hZHl2RTN1eFpHcGY0V1JG?= =?utf-8?B?dFNXNFRwQi9pTzVsLzZWUXBVS0c5L1NSaWhOL09TL3BjMzRKNDlaZ2Qzb3Fp?= =?utf-8?B?T09vekJBdEJWNytSMXBFUjQrOFg1TlRpN0VoYzBpVkpHZ1U2MUhPTHpLSEMr?= =?utf-8?B?b1ZZTkJ2MXo5S3gwMXhKN05SUExaUGJYbnY5czk4a3llaDh1VWc1VXN0NElO?= =?utf-8?B?STdUbVhtTTdocDlUeGVFYXRmd2x3SW51YTVoUlpweDl2eHd3eUk0UG41UDdh?= =?utf-8?B?T1dtVHRreVlBb2E4bFVCVHhjckdEbkFSeDVGbVdRVEpRc1llZk1vMm1wWkk3?= =?utf-8?B?NlBlK3FNbGxXeEdpLzBFUFl3blpqVXZTVUtRbW1Ea2FHc1RZTnB1RWVQVkR1?= =?utf-8?B?YnQyRFN2YXVXTEtENitjOXo2aWRibkVpNXpOK1hSRUxZdDV5UUdZZXlkZi9C?= =?utf-8?B?ZW5LVlJrYTR0N3crR0pCbzlBQzloeXNGSWtUKzBYcDlQcEcrSmJlMlVsL2R2?= =?utf-8?B?ckUxYjRsekpQS29zcVNlZ0NHVVQ4eTl0OE56czA1bk5PcTZZZEg4M1ZzSzR3?= =?utf-8?B?UjlXQXErd1orS3Fra3FtSUVGMGlTZm9kY0huUkdpaVcwWWxDbWRYcURvcEV6?= =?utf-8?B?Zjc2bU1yVnpraW16L1NVY0JTVStyeVRpdkZJWWY2M3NPUWt2WmdoVXdJREZT?= =?utf-8?B?Y2FkOGVFbStJQmxweDI5QTJRdjVKNk53bmtEblNVVDBwRlllUExYbVQ1cDlh?= =?utf-8?B?bGNyOW9INnZsKzlNd0t1WWlUUXVqaEtFQ3FlWlYwZzFhTlE0RUJSOXJRRFdq?= =?utf-8?B?RlNWcmRobThlc251Ry9vRHFpK3NSalV0NlBuamRXK0piUGR3OTZ1Wkc4bFo2?= =?utf-8?B?R2JLVmtMaHhPRkE9PQ==?= X-MS-Exchange-CrossTenant-AuthSource: BYAPR15MB4088.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Dec 2020 07:32:02.8808 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-Network-Message-Id: 67040cb3-7c71-445c-077f-08d8a7de01ea X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: xFSsyfkrwKvw65EeCqZ8PcJQkoyWTTB0o7w2mBMaVkKI4JiR4TwZs/NH1avbCqfA X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2246 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343,18.0.737 definitions=2020-12-24_05:2020-12-24,2020-12-24 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 clxscore=1011 mlxscore=0 bulkscore=0 impostorscore=0 suspectscore=0 phishscore=0 priorityscore=1501 spamscore=0 mlxlogscore=999 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012240045 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/23/20 11:01 PM, YANG LI wrote: > Assigning local variable txq to the outputting parameter xdp->txq is not > safe, txq will be released after the end of the function call. > Then the result of using xdp is unpredictable. > > Fix this error by defining the struct xdp_txq_info in function > dev_map_run_prog() as a static type. > > Signed-off-by: YANG LI > Reported-by: Abaci > --- > kernel/bpf/devmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index f6e9c68..af6f004 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c > @@ -454,7 +454,7 @@ static struct xdp_buff *dev_map_run_prog(struct net_device *dev, > struct xdp_buff *xdp, > struct bpf_prog *xdp_prog) > { > - struct xdp_txq_info txq = { .dev = dev }; > + static struct xdp_txq_info txq = { .dev = dev }; > u32 act; > > xdp_set_data_meta_invalid(xdp); exposing txq outside the routine with 'static' definition is not a good practice. maybe just reset xdp->txq = NULl right before function return? diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index f6e9c68afdd4..50f5c20a33a3 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -475,6 +475,7 @@ static struct xdp_buff *dev_map_run_prog(struct net_device *dev, } xdp_return_buff(xdp); + xdp->txq = NULL; return NULL; } -bash-4.4$