From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELurObmvtYkVbhYH9sNYY8oiNIZxphMXyAp+00/HGs9fuL2L9zmf4/Bt3LMi28z5aokrCkRL ARC-Seal: i=1; a=rsa-sha256; t=1521214157; cv=none; d=google.com; s=arc-20160816; b=kRTBRSAtbkXyJviAmzGRlsanimtBacFc8QYk86d36sEmmJIH83JFDz6hfBX5cK0KX6 x0jlnysl+NkTvqb2dQpcPezcyMuhDMZCs9SzgCaK29XhhayKrIoP9r109eyX0Q2lAWnA bIOq8EY3axJaA6vUvZt8oHgxl396vQB5LCoNZOCpcUr2y83VnrHdENQjflcFbbYxdNrV 9LGKP/1EFxpFScbYxyYqe9RUoadlxVlB5wqhSvJ30iIgBEIERha8MaCGcZ2QBJAz1v98 rwOaNOpQ2inBmTLZBSIuzOKRwCyxcVBcSSWa9j9QbhQkyB79L0JZ2MdlHIiPFJCT0DNI v0ug== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=jQfMWnYrXZVju3BrMaIhgJr+ECCE/ygwenTQBxBKNpo=; b=owKQDtn3sAE2JBbwc/v2yusZA0tzNR1JXGkDpuG9mJTs5mTFFdrCbTMNL4unLJZdF+ EboiMvwKhn4ICwBgDPg9J5tPCez1UMe4GjK8PC9BRugbeV1LaoinONd6UehEunGYjD9e izjm3xiXhOnn2r3+vsyW2kVh43Z06229sgMm/q1IRm0iDGT+Kw1Jy0BGoOuwgGwP8I7Y 8VU1gVTkkAGjLJ1/qNeWWpd4dI+ZBKF2ec1cbE0VsoZ0QhfU2c64IhkryKE1kCbUoR11 6fR4DnVSy2y7TxQVKkhuMQGRaYslW5v6PgwGy9El2lvTx+erymu/sb5NIeJW57RtcCu2 FeBA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fredrik Noring , Pete Zaitcev Subject: [PATCH 4.4 60/63] usb: usbmon: Read text within supplied buffer size Date: Fri, 16 Mar 2018 16:23:32 +0100 Message-Id: <20180316152306.545131645@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180316152259.964532775@linuxfoundation.org> References: <20180316152259.964532775@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595108322348681273?= X-GMAIL-MSGID: =?utf-8?q?1595108656571925033?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pete Zaitcev commit a5f596830e27e15f7a0ecd6be55e433d776986d8 upstream. This change fixes buffer overflows and silent data corruption with the usbmon device driver text file read operations. Signed-off-by: Fredrik Noring Signed-off-by: Pete Zaitcev Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/mon/mon_text.c | 124 +++++++++++++++++++++++++++------------------ 1 file changed, 77 insertions(+), 47 deletions(-) --- a/drivers/usb/mon/mon_text.c +++ b/drivers/usb/mon/mon_text.c @@ -82,6 +82,8 @@ struct mon_reader_text { wait_queue_head_t wait; int printf_size; + size_t printf_offset; + size_t printf_togo; char *printf_buf; struct mutex printf_lock; @@ -373,75 +375,103 @@ err_alloc: return rc; } -/* - * For simplicity, we read one record in one system call and throw out - * what does not fit. This means that the following does not work: - * dd if=/dbg/usbmon/0t bs=10 - * Also, we do not allow seeks and do not bother advancing the offset. - */ +static ssize_t mon_text_copy_to_user(struct mon_reader_text *rp, + char __user * const buf, const size_t nbytes) +{ + const size_t togo = min(nbytes, rp->printf_togo); + + if (copy_to_user(buf, &rp->printf_buf[rp->printf_offset], togo)) + return -EFAULT; + rp->printf_togo -= togo; + rp->printf_offset += togo; + return togo; +} + +/* ppos is not advanced since the llseek operation is not permitted. */ static ssize_t mon_text_read_t(struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) + size_t nbytes, loff_t *ppos) { struct mon_reader_text *rp = file->private_data; struct mon_event_text *ep; struct mon_text_ptr ptr; + ssize_t ret; - ep = mon_text_read_wait(rp, file); - if (IS_ERR(ep)) - return PTR_ERR(ep); mutex_lock(&rp->printf_lock); - ptr.cnt = 0; - ptr.pbuf = rp->printf_buf; - ptr.limit = rp->printf_size; - - mon_text_read_head_t(rp, &ptr, ep); - mon_text_read_statset(rp, &ptr, ep); - ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, - " %d", ep->length); - mon_text_read_data(rp, &ptr, ep); - if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) - ptr.cnt = -EFAULT; + if (rp->printf_togo == 0) { + + ep = mon_text_read_wait(rp, file); + if (IS_ERR(ep)) { + mutex_unlock(&rp->printf_lock); + return PTR_ERR(ep); + } + ptr.cnt = 0; + ptr.pbuf = rp->printf_buf; + ptr.limit = rp->printf_size; + + mon_text_read_head_t(rp, &ptr, ep); + mon_text_read_statset(rp, &ptr, ep); + ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, + " %d", ep->length); + mon_text_read_data(rp, &ptr, ep); + + rp->printf_togo = ptr.cnt; + rp->printf_offset = 0; + + kmem_cache_free(rp->e_slab, ep); + } + + ret = mon_text_copy_to_user(rp, buf, nbytes); mutex_unlock(&rp->printf_lock); - kmem_cache_free(rp->e_slab, ep); - return ptr.cnt; + return ret; } +/* ppos is not advanced since the llseek operation is not permitted. */ static ssize_t mon_text_read_u(struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) + size_t nbytes, loff_t *ppos) { struct mon_reader_text *rp = file->private_data; struct mon_event_text *ep; struct mon_text_ptr ptr; + ssize_t ret; - ep = mon_text_read_wait(rp, file); - if (IS_ERR(ep)) - return PTR_ERR(ep); mutex_lock(&rp->printf_lock); - ptr.cnt = 0; - ptr.pbuf = rp->printf_buf; - ptr.limit = rp->printf_size; - mon_text_read_head_u(rp, &ptr, ep); - if (ep->type == 'E') { - mon_text_read_statset(rp, &ptr, ep); - } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { - mon_text_read_isostat(rp, &ptr, ep); - mon_text_read_isodesc(rp, &ptr, ep); - } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { - mon_text_read_intstat(rp, &ptr, ep); - } else { - mon_text_read_statset(rp, &ptr, ep); + if (rp->printf_togo == 0) { + + ep = mon_text_read_wait(rp, file); + if (IS_ERR(ep)) { + mutex_unlock(&rp->printf_lock); + return PTR_ERR(ep); + } + ptr.cnt = 0; + ptr.pbuf = rp->printf_buf; + ptr.limit = rp->printf_size; + + mon_text_read_head_u(rp, &ptr, ep); + if (ep->type == 'E') { + mon_text_read_statset(rp, &ptr, ep); + } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { + mon_text_read_isostat(rp, &ptr, ep); + mon_text_read_isodesc(rp, &ptr, ep); + } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { + mon_text_read_intstat(rp, &ptr, ep); + } else { + mon_text_read_statset(rp, &ptr, ep); + } + ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, + " %d", ep->length); + mon_text_read_data(rp, &ptr, ep); + + rp->printf_togo = ptr.cnt; + rp->printf_offset = 0; + + kmem_cache_free(rp->e_slab, ep); } - ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, - " %d", ep->length); - mon_text_read_data(rp, &ptr, ep); - if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) - ptr.cnt = -EFAULT; + ret = mon_text_copy_to_user(rp, buf, nbytes); mutex_unlock(&rp->printf_lock); - kmem_cache_free(rp->e_slab, ep); - return ptr.cnt; + return ret; } static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,