From nobody Fri Jan 2 22:09:47 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 0EA65E81E16 for ; Sat, 7 Oct 2023 03:42:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343508AbjJGDmB (ORCPT ); Fri, 6 Oct 2023 23:42:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234043AbjJGDl6 (ORCPT ); Fri, 6 Oct 2023 23:41:58 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4C06BD for ; Fri, 6 Oct 2023 20:41:54 -0700 (PDT) Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3973ckNd031558; Sat, 7 Oct 2023 03:41:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=AO32nXH08dML1T+/b42a6LXZnMlL1YQ3mKO0J4C7mZw=; b=c0Np81fY7qgzdx3tGRlO2CkT+HSFWeg1SyLf+LNJjNSjXc037kNoiYgp4rZSNgf4TFwr SOYpiKzv+gHVLMZnsSEMLJBnomL9mh8SSKGHInL2RujZ/nFoJd9g2jHtMVLn9XLde8gi 3dU/IeiuIayXR3hQvV2hsiahgM+U91MDD6ce0DvJyW5Ym9h5dkCcHmHCaHZkfS4jOr59 eMFzCFe5+9hv5HZFjCdU3s2isiGC7YbX+KDyOS+pFxj8D5n9WxDsV61p5/z1gCrCzjRh f0ulhni3zvfb4/NTcM5yDIeJkuLdBxK+Lsxug1VpEVCAUNOVOw61F5VJfqxNVyzncU3q iQ== Received: from nalasppmta03.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3tjye0g0jy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 07 Oct 2023 03:41:47 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA03.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3973fkKp028746 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 7 Oct 2023 03:41:46 GMT Received: from maow2-gv.qualcomm.com (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 15.2.1118.36; Fri, 6 Oct 2023 20:41:43 -0700 From: Kassey Li To: , , , , , , CC: , , , Subject: [PATCH] binder: add mutex_lock for mmap and NULL when free Date: Sat, 7 Oct 2023 11:40:46 +0800 Message-ID: <20231007034046.2352124-1-quic_yingangl@quicinc.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 3bZaDyX8RnILZJcVdY4luaHmsa38cQDG X-Proofpoint-ORIG-GUID: 3bZaDyX8RnILZJcVdY4luaHmsa38cQDG X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-06_15,2023-10-06_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 clxscore=1011 impostorscore=0 mlxscore=0 mlxlogscore=911 spamscore=0 adultscore=0 priorityscore=1501 phishscore=0 bulkscore=0 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310070031 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Enforce alloc->mutex in binder_alloc_mmap_handler when add the entry to list. Assign the freed pages/page_ptr to NULL to catch possible use after free with NULL pointer access. Signed-off-by: Kassey Li --- drivers/android/binder_alloc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index e3db8297095a..c7d126e04343 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -775,6 +775,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *allo= c, } =20 buffer->user_data =3D alloc->buffer; + mutex_lock(&alloc->mutex); list_add(&buffer->entry, &alloc->buffers); buffer->free =3D 1; binder_insert_free_buffer(alloc, buffer); @@ -782,7 +783,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *allo= c, =20 /* Signal binder_alloc is fully initialized */ binder_alloc_set_vma(alloc, vma); - + mutex_unlock(&alloc->mutex); return 0; =20 err_alloc_buf_struct_failed: @@ -856,9 +857,11 @@ void binder_alloc_deferred_release(struct binder_alloc= *alloc) __func__, alloc->pid, i, page_addr, on_lru ? "on lru" : "active"); __free_page(alloc->pages[i].page_ptr); + alloc->pages[i].page_ptr =3D NULL; page_count++; } kfree(alloc->pages); + alloc->pages =3D NULL; } mutex_unlock(&alloc->mutex); if (alloc->mm) --=20 2.25.1