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 44C13C46CA1 for ; Thu, 12 Oct 2023 00:25:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376620AbjJLAZC (ORCPT ); Wed, 11 Oct 2023 20:25:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231381AbjJLAZA (ORCPT ); Wed, 11 Oct 2023 20:25:00 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54D5294 for ; Wed, 11 Oct 2023 17:24:58 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id 41be03b00d2f7-56f75e70190so268398a12.3 for ; Wed, 11 Oct 2023 17:24:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697070298; x=1697675098; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=btfnS5sl+NHrJw3NusDcQHMvqgT7weLrRVmIEylNtmA=; b=paV3ju6qfLYkT/XRvfoREwdzlTmtv+EQVM6If6Jz5RSfaMh59/TTOqWhwXtcrREBqt 1O2fg9x5NuK5qJUT+9zqsVKrhcE61l64A7ivbHKEgQbCyrxsh4y3tWz2plEgZdtKOVBt kyQgsLzSsUfvMLK74CwYQtkCEQZMt0UDQQb+ySVimOO8khsKuiTWOhRFt122GpTIMVQI DP8756LJS9yRJTkUFrmJ3B/kxcNpQqRmjoJlZdbw97+M5MzIssqCUv6DzN1Swrh2y5wh Zy/tHVTEZaCuhphw+Vq5AkbPw1CG5k/m6Vh0yHiFMHsAl54sfharjvqUhhbtrkvx9CQA TTrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697070298; x=1697675098; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=btfnS5sl+NHrJw3NusDcQHMvqgT7weLrRVmIEylNtmA=; b=Fmskpd2XqGt926N6S3NB5TPRxQKSPJ+p2Kh+3tzmWB8Jr3dprUCTqVab4zkY9sCirq 99ecZ4Sv3F4NqkYDeYBA7QerAkc9rFktlrOndLdvHJTYqNz+RiXjczVuRmLr5JK2LZMV 2Pvp6eHPmT6FK7Qeet5in5IoXOJfte3t141OajEiBoFIVZE5/gTknI5YbmXipsEb9j2n xoNkLAvZ2q6f/SantGH1nybKNJrxEkrgC08VomAHzMd2RUgheKuWuUelaTlIqPFHHzy2 qPkY1m3tiu/th8A4JaffmDmRtJvgKcwOcDpnHqorGhOtJnznZxvBAkojDHE5okEeVjT4 ajvg== X-Gm-Message-State: AOJu0YxxLGc19eEb7VU4REPMVj67GJivv49CkRhhh4GvUDLL4Pt3EJx4 bnWuj82tQNBMqWAnjA/HKoIbN51mJc9A X-Google-Smtp-Source: AGHT+IFkXksa1r4zdeZT+337VviFgmSvR5/z6pHlzhvvCuIpqKu0DhChxAcs5Rcd1zZev52Pa3eTJlNUHudI X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a63:2955:0:b0:57e:2432:b384 with SMTP id bu21-20020a632955000000b0057e2432b384mr380748pgb.0.1697070297859; Wed, 11 Oct 2023 17:24:57 -0700 (PDT) Date: Wed, 11 Oct 2023 17:24:50 -0700 In-Reply-To: <20231012002451.254737-1-arakesh@google.com> Mime-Version: 1.0 References: <20230930184821.310143-1-arakesh@google.com> <20231012002451.254737-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Message-ID: <20231012002451.254737-2-arakesh@google.com> Subject: [PATCH v4 2/3] usb: gadget: uvc: Allocate uvc_requests one at a time From: Avichal Rakesh To: arakesh@google.com, dan.scally@ideasonboard.com, laurent.pinchart@ideasonboard.com, m.grzeschik@pengutronix.de Cc: etalvala@google.com, gregkh@linuxfoundation.org, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, the uvc gadget driver allocates all uvc_requests as one array and deallocates them all when the video stream stops. This includes de-allocating all the usb_requests associated with those uvc_requests. This can lead to use-after-free issues if any of those de-allocated usb_requests were still owned by the usb controller. This patch is 1 of 2 patches addressing the use-after-free issue. Instead of bulk allocating all uvc_requests as an array, this patch allocates uvc_requests one at a time, which should allows for similar granularity when deallocating the uvc_requests. This patch has no functional changes other than allocating each uvc_request separately, and similarly freeing each of them separately. Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com Suggested-by: Michael Grzeschik Reviewed-by: Michael Grzeschik Signed-off-by: Avichal Rakesh --- v1 -> v2: Rebased to ToT v2 -> v3: Fix email threading goof-up v3 -> v4: Address review comments & re-rebase to ToT drivers/usb/gadget/function/uvc.h | 3 +- drivers/usb/gadget/function/uvc_video.c | 87 ++++++++++++++----------- 2 files changed, 50 insertions(+), 40 deletions(-) diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 989bc6b4e93d..993694da0bbc 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -81,6 +81,7 @@ struct uvc_request { struct sg_table sgt; u8 header[UVCG_REQUEST_HEADER_LEN]; struct uvc_buffer *last_buf; + struct list_head list; }; struct uvc_video { @@ -102,7 +103,7 @@ struct uvc_video { /* Requests */ unsigned int req_size; - struct uvc_request *ureq; + struct list_head ureqs; /* all uvc_requests allocated by uvc_video */ struct list_head req_free; spinlock_t req_lock; diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index c334802ac0a4..b62b3de79153 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -227,6 +227,24 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, * Request handling */ +static void +uvc_video_free_request(struct uvc_request *ureq, struct usb_ep *ep) +{ + sg_free_table(&ureq->sgt); + if (ureq->req && ep) { + usb_ep_free_request(ep, ureq->req); + ureq->req = NULL; + } + + kfree(ureq->req_buffer); + ureq->req_buffer = NULL; + + if (!list_empty(&ureq->list)) + list_del_init(&ureq->list); + + kfree(ureq); +} + static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) { int ret; @@ -293,27 +311,12 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) static int uvc_video_free_requests(struct uvc_video *video) { - unsigned int i; + struct uvc_request *ureq, *temp; - if (video->ureq) { - for (i = 0; i < video->uvc_num_requests; ++i) { - sg_free_table(&video->ureq[i].sgt); - - if (video->ureq[i].req) { - usb_ep_free_request(video->ep, video->ureq[i].req); - video->ureq[i].req = NULL; - } - - if (video->ureq[i].req_buffer) { - kfree(video->ureq[i].req_buffer); - video->ureq[i].req_buffer = NULL; - } - } - - kfree(video->ureq); - video->ureq = NULL; - } + list_for_each_entry_safe(ureq, temp, &video->ureqs, list) + uvc_video_free_request(ureq, video->ep); + INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); video->req_size = 0; return 0; @@ -322,6 +325,7 @@ uvc_video_free_requests(struct uvc_video *video) static int uvc_video_alloc_requests(struct uvc_video *video) { + struct uvc_request *ureq; unsigned int req_size; unsigned int i; int ret = -ENOMEM; @@ -332,29 +336,32 @@ uvc_video_alloc_requests(struct uvc_video *video) * max_t(unsigned int, video->ep->maxburst, 1) * (video->ep->mult); - video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL); - if (video->ureq == NULL) - return -ENOMEM; + INIT_LIST_HEAD(&video->ureqs); + for (i = 0; i < video->uvc_num_requests; i++) { + ureq = kzalloc(sizeof(struct uvc_request), GFP_KERNEL); + if (ureq == NULL) + goto error; + INIT_LIST_HEAD(&ureq->list); + list_add_tail(&ureq->list, &video->ureqs); - for (i = 0; i < video->uvc_num_requests; ++i) { - video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL); - if (video->ureq[i].req_buffer == NULL) + ureq->req_buffer = kmalloc(req_size, GFP_KERNEL); + if (ureq->req_buffer == NULL) goto error; - video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); - if (video->ureq[i].req == NULL) + ureq->req = usb_ep_alloc_request(video->ep, GFP_KERNEL); + if (ureq->req == NULL) goto error; - video->ureq[i].req->buf = video->ureq[i].req_buffer; - video->ureq[i].req->length = 0; - video->ureq[i].req->complete = uvc_video_complete; - video->ureq[i].req->context = &video->ureq[i]; - video->ureq[i].video = video; - video->ureq[i].last_buf = NULL; + ureq->req->buf = ureq->req_buffer; + ureq->req->length = 0; + ureq->req->complete = uvc_video_complete; + ureq->req->context = ureq; + ureq->video = video; + ureq->last_buf = NULL; - list_add_tail(&video->ureq[i].req->list, &video->req_free); + list_add_tail(&ureq->req->list, &video->req_free); /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ - sg_alloc_table(&video->ureq[i].sgt, + sg_alloc_table(&ureq->sgt, DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN, PAGE_SIZE) + 2, GFP_KERNEL); } @@ -489,8 +496,8 @@ static void uvcg_video_pump(struct work_struct *work) */ int uvcg_video_enable(struct uvc_video *video, int enable) { - unsigned int i; int ret; + struct uvc_request *ureq; if (video->ep == NULL) { uvcg_info(&video->uvc->func, @@ -502,9 +509,10 @@ int uvcg_video_enable(struct uvc_video *video, int enable) cancel_work_sync(&video->pump); uvcg_queue_cancel(&video->queue, 0); - for (i = 0; i < video->uvc_num_requests; ++i) - if (video->ureq && video->ureq[i].req) - usb_ep_dequeue(video->ep, video->ureq[i].req); + list_for_each_entry(ureq, &video->ureqs, list) { + if (ureq->req) + usb_ep_dequeue(video->ep, ureq->req); + } uvc_video_free_requests(video); uvcg_queue_enable(&video->queue, 0); @@ -536,6 +544,7 @@ int uvcg_video_enable(struct uvc_video *video, int enable) */ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) { + INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); spin_lock_init(&video->req_lock); INIT_WORK(&video->pump, uvcg_video_pump); -- 2.42.0.609.gbb76f46606-goog