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[23.128.96.18]) by mx.google.com with ESMTP id g11si503680eje.65.2021.05.30.20.02.46; Sun, 30 May 2021 20:03:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230013AbhEaDD3 (ORCPT + 99 others); Sun, 30 May 2021 23:03:29 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:3297 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230034AbhEaDD1 (ORCPT ); Sun, 30 May 2021 23:03:27 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Ftg165dg2z1BGjj; Mon, 31 May 2021 10:56:42 +0800 (CST) Received: from dggpeml500017.china.huawei.com (7.185.36.243) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 31 May 2021 11:01:22 +0800 Received: from huawei.com (10.175.103.91) by dggpeml500017.china.huawei.com (7.185.36.243) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 31 May 2021 11:01:22 +0800 From: Yang Yingliang To: , , CC: , , , Subject: [PATCH -next v2] cifsd: check return value of ksmbd_vfs_getcasexattr() correctly Date: Mon, 31 May 2021 11:05:50 +0800 Message-ID: <20210531030550.1708816-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.103.91] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500017.china.huawei.com (7.185.36.243) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If ksmbd_vfs_getcasexattr() returns -ENOMEM, stream_buf is NULL, it will cause null-ptr-deref when using it to copy memory. So we need check the return value of ksmbd_vfs_getcasexattr() by comparing with 0. Fixes: f44158485826 ("cifsd: add file operations") Signed-off-by: Yang Yingliang --- v2: Handle the case ksmbd_vfs_getcasexattr() returns 0. --- fs/cifsd/vfs.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/cifsd/vfs.c b/fs/cifsd/vfs.c index 97d5584ec870..2a9cc0bc7726 100644 --- a/fs/cifsd/vfs.c +++ b/fs/cifsd/vfs.c @@ -274,7 +274,6 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos, { ssize_t v_len; char *stream_buf = NULL; - int err; ksmbd_debug(VFS, "read stream data pos : %llu, count : %zd\n", *pos, count); @@ -283,10 +282,9 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos, fp->stream.name, fp->stream.size, &stream_buf); - if (v_len == -ENOENT) { + if ((int)v_len <= 0) { ksmbd_err("not found stream in xattr : %zd\n", v_len); - err = -ENOENT; - return err; + return v_len == 0 ? -ENOENT : (int)v_len; } memcpy(buf, &stream_buf[*pos], count); @@ -415,9 +413,9 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos, fp->stream.name, fp->stream.size, &stream_buf); - if (v_len == -ENOENT) { + if ((int)v_len <= 0) { ksmbd_err("not found stream in xattr : %zd\n", v_len); - err = -ENOENT; + err = v_len == 0 ? -ENOENT : (int)v_len; goto out; } -- 2.25.1