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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DBBAECAAD8 for ; Thu, 22 Sep 2022 00:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230103AbiIVAjF (ORCPT ); Wed, 21 Sep 2022 20:39:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229745AbiIVAjB (ORCPT ); Wed, 21 Sep 2022 20:39:01 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A2DFA98D5 for ; Wed, 21 Sep 2022 17:39:00 -0700 (PDT) Received: from pps.filterd (m0279867.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28M0EEY7015983; Thu, 22 Sep 2022 00:38:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : from : subject : to : cc : references : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=WOKnIKyfnSQpXihINowX2QmhIeEEpjddrkKFnyBcaDQ=; b=PnW0qtQehedV7849wzvDD0pzXZlxvWyyLSXQ6kEPqmjd8pIIEL43uYUbAPdxh09QXwMv uGLnQ5IQFgM6r+J2d3EF49b+wdhn4/cneeroH4Hbwwx8OueTS/P6G/TlQQmbwgTm8WHy nToRy8CidvUN7KCHpwujpskGV4TjCU51uBNMA9FSvWBEkET/QPJUzVyugWzwrFzscmK/ PHam23hjy2OZGt8YrHrNsZrFoa6VpZ8VTxLk2FIVAwV9MHOiBpDvqIoIOa3nkca9kq/O 9kJX/YYdDL0tQq5D/t2hvTCYn4EGxVSjwgSEEefIGz3yuDvlDoSrrQt/UOv/wxYAOliU dQ== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3jr4ge1pwf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Sep 2022 00:38:46 +0000 Received: from pps.filterd (NALASPPMTA01.qualcomm.com [127.0.0.1]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTP id 28M0Q3M8032182; Thu, 22 Sep 2022 00:33:40 GMT Received: from pps.reinject (localhost [127.0.0.1]) by NALASPPMTA01.qualcomm.com (PPS) with ESMTPS id 3jnqr800b6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Sep 2022 00:33:40 +0000 Received: from NALASPPMTA01.qualcomm.com (NALASPPMTA01.qualcomm.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 28M0Xd0g008432; Thu, 22 Sep 2022 00:33:39 GMT Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA01.qualcomm.com (PPS) with ESMTPS id 28M0Xdii008430 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Sep 2022 00:33:39 +0000 Received: from [10.232.65.248] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Wed, 21 Sep 2022 17:33:38 -0700 Message-ID: Date: Thu, 22 Sep 2022 08:33:35 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.0.3 From: Kassey Li Subject: Re: [PATCH] cgroup: align the comm length with TASK_COMM_LEN To: , , , CC: References: <20220920084923.18476-1-quic_yingangl@quicinc.com> Content-Language: en-US In-Reply-To: <20220920084923.18476-1-quic_yingangl@quicinc.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: S2d9lGKw8KUWOXQfboA_4O-kfBG6L4KA X-Proofpoint-ORIG-GUID: S2d9lGKw8KUWOXQfboA_4O-kfBG6L4KA X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-21_13,2022-09-20_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 lowpriorityscore=0 mlxlogscore=677 adultscore=0 suspectscore=0 clxscore=1015 mlxscore=0 priorityscore=1501 bulkscore=0 malwarescore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2209220002 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hello: here is the instance of the problem： may you kindly review this change ? Unable to handle kernel write to read-only memory at virtual address ffffffbcf7450000 Call trace: dump_backtrace.cfi_jt+0x0/0x4 show_stack+0x14/0x1c dump_stack+0xa0/0xd8 die_callback+0x248/0x24c notify_die+0x7c/0xf8 die+0xac/0x290 die_kernel_fault+0x88/0x98 die_kernel_fault+0x0/0x98 do_page_fault+0xa0/0x544 do_mem_abort+0x60/0x10c el1_da+0x1c/0xc4 trace_event_raw_event_cgroup_migrate+0x124/0x170 cgroup_attach_task+0x2e8/0x41c __cgroup1_procs_write+0x114/0x1ec cgroup1_tasks_write+0x10/0x18 cgroup_file_write+0xa4/0x208 kernfs_fop_write+0x1f0/0x2f4 __vfs_write+0x5c/0x200 vfs_write+0xe0/0x1a0 ksys_write+0x74/0xdc __arm64_sys_write+0x18/0x20 el0_svc_common+0xc0/0x1a4 el0_svc_compat_handler+0x18/0x20 el0_svc_compat+0x8/0x2c On 9/20/2022 4:49 PM, Kassey Li wrote: > __string could get a dst string with length less than > TASK_COMM_LEN. > > a task->comm possbile change dynamic that can cause > out of bounds access for the dst string buffer. > > change it as arrary with same length TASK_COMM_LEN, > this aligns the same usage of include/trace on task->comm. > > Signed-off-by: Kassey Li > --- > include/trace/events/cgroup.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/trace/events/cgroup.h b/include/trace/events/cgroup.h > index dd7d7c9efecd..d0c5f93e3611 100644 > --- a/include/trace/events/cgroup.h > +++ b/include/trace/events/cgroup.h > @@ -130,7 +130,7 @@ DECLARE_EVENT_CLASS(cgroup_migrate, > __field( u64, dst_id ) > __field( int, pid ) > __string( dst_path, path ) > - __string( comm, task->comm ) > + __array(char, comm, TASK_COMM_LEN) > ), > > TP_fast_assign( > @@ -139,12 +139,12 @@ DECLARE_EVENT_CLASS(cgroup_migrate, > __entry->dst_level = dst_cgrp->level; > __assign_str(dst_path, path); > __entry->pid = task->pid; > - __assign_str(comm, task->comm); > + memcpy(__entry->comm, task->comm, TASK_COMM_LEN); > ), > > TP_printk("dst_root=%d dst_id=%llu dst_level=%d dst_path=%s pid=%d comm=%s", > __entry->dst_root, __entry->dst_id, __entry->dst_level, > - __get_str(dst_path), __entry->pid, __get_str(comm)) > + __get_str(dst_path), __entry->pid, __entry->comm) > ); > > DEFINE_EVENT(cgroup_migrate, cgroup_attach_task,