From nobody Thu Apr 2 13:08:28 2026 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 684C0C6FA82 for ; Fri, 23 Sep 2022 07:51:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230351AbiIWHvV (ORCPT ); Fri, 23 Sep 2022 03:51:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229844AbiIWHvT (ORCPT ); Fri, 23 Sep 2022 03:51:19 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DBE712870A for ; Fri, 23 Sep 2022 00:51:18 -0700 (PDT) Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28N7RiQN021805; Fri, 23 Sep 2022 07:51:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id; s=qcppdkim1; bh=7MbLR4PVl/QPaimY1DxV2Mx73E36ktNnZAiObx7PFHQ=; b=HYX9apiGDaHkI9rf0Q/s15YRmGfS1fStkdtm0JOuzxRL6FRU9nB2cyrrTNSI1rTLQjSp qn946DuM5j7w8ajM75lspvVFjcFvCG0bBOR3SNCkwaphAebQnDNtRA3MaHzU9Xiopfpk 88d7OEOOpEbpzNzaC6v4Dpc5E1jCqWyATf1fHKgRDBv3u7vPses0OyRC7fLrUC42W24b yoQsyYhXX+wc3CIL9nAI7x9SUERljXTHA6N3AbpOmGZRRJNmrXAC3wU0rcVfHM3vTTLm U+dyXV85vJbS1DYqT7bNx9MZDxUK06dPC/1Xd7OSM4T+zIHujmsSmiUvhe64ym65Ek3s hg== Received: from aptaippmta02.qualcomm.com (tpe-colo-wan-fw-bordernet.qualcomm.com [103.229.16.4]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3jrpqntav9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 23 Sep 2022 07:51:12 +0000 Received: from pps.filterd (APTAIPPMTA02.qualcomm.com [127.0.0.1]) by APTAIPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTP id 28N7p9pN027934; Fri, 23 Sep 2022 07:51:09 GMT Received: from pps.reinject (localhost [127.0.0.1]) by APTAIPPMTA02.qualcomm.com (PPS) with ESMTPS id 3jnqnufjwa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 23 Sep 2022 07:51:09 +0000 Received: from APTAIPPMTA02.qualcomm.com (APTAIPPMTA02.qualcomm.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 28N7p8Qc027925; Fri, 23 Sep 2022 07:51:09 GMT Received: from maow2-gv.ap.qualcomm.com (maow2-gv.qualcomm.com [10.232.193.133]) by APTAIPPMTA02.qualcomm.com (PPS) with ESMTP id 28N7p8vQ027924; Fri, 23 Sep 2022 07:51:08 +0000 Received: by maow2-gv.ap.qualcomm.com (Postfix, from userid 399080) id 4A80D21029A4; Fri, 23 Sep 2022 15:51:07 +0800 (CST) From: Kassey Li To: rostedt@goodmis.org, mingo@redhat.com, tj@kernel.org, william.kucharski@oracle.com Cc: Kassey Li , linux-kernel@vger.kernel.org Subject: [PATCH v2] cgroup: align the comm length with TASK_COMM_LEN Date: Fri, 23 Sep 2022 15:51:05 +0800 Message-Id: <20220923075105.28251-1-quic_yingangl@quicinc.com> X-Mailer: git-send-email 2.17.1 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-ORIG-GUID: d5toZqgqwsVHRU-bOopcGMAUoKoUu4rx X-Proofpoint-GUID: d5toZqgqwsVHRU-bOopcGMAUoKoUu4rx 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=2022-09-23_02,2022-09-22_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxscore=0 malwarescore=0 phishscore=0 impostorscore=0 mlxlogscore=444 lowpriorityscore=0 bulkscore=0 spamscore=0 priorityscore=1501 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2209230050 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" __string could get a dst string with length less than TASK_COMM_LEN. A task->comm may change that can cause out of bounds access for the dst string buffer, e.g in the call trace of below: 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 Change it as arrary with same length TASK_COMM_LEN, This idea is from commit d1eb650ff413 ("tracepoint: Move signal sending tracepoint to events/signal.h"). 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..b4ef0ffa38a4 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) ), =20 TP_fast_assign( @@ -139,12 +139,12 @@ DECLARE_EVENT_CLASS(cgroup_migrate, __entry->dst_level =3D dst_cgrp->level; __assign_str(dst_path, path); __entry->pid =3D task->pid; - __assign_str(comm, task->comm); + memcpy(__entry->comm, task->comm, TASK_COMM_LEN); ), =20 TP_printk("dst_root=3D%d dst_id=3D%llu dst_level=3D%d dst_path=3D%s pid= =3D%d comm=3D%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) ); =20 DEFINE_EVENT(cgroup_migrate, cgroup_attach_task, --=20 2.17.1