From patchwork Thu Oct 12 00:24:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13418092 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1892019B for ; Thu, 12 Oct 2023 00:24:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IQ7LCc4d" Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CD6790 for ; Wed, 11 Oct 2023 17:24:55 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id 98e67ed59e1d1-27d1aee59feso310033a91.0 for ; Wed, 11 Oct 2023 17:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697070295; x=1697675095; 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=TG++fvWfitw/Sd3Hpgv4FLh87i4JPu5cxo2T/O4RJwY=; b=IQ7LCc4dLlKSkhl/k/jDiI6c6qxEapg6q03XfT+vMZt/x6+16yOiUq4zLS8KnCRBEd s3beUpzLqnK3yJ6QavMqqgcsL6GbjizRR6HdI9Af32TX26zaTkAPDi4WeFNOkNxVTkME 2FyvtiLucNPxALbvDGfQSW4cpIIi6cQNXKvbyNOP//qbeDB9LL2BkVGHjuwBwClHXj7U Aa637zUHDVlepYSQH4bfiwxw5CrNnKeImblV621OlWgvJciTJDnfKOBv3Pp2b3IKAm4v NvZYsQTouwY4LkppeCC8nJ1bsOWhaaaZDPJrHw911uBRGrmQN9vJeMQ3ZyR59mYqRuJH 04IQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697070295; x=1697675095; 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=TG++fvWfitw/Sd3Hpgv4FLh87i4JPu5cxo2T/O4RJwY=; b=N9Bn3o5Oa90d98fLNjtsYs9LyJbSJE8MmkELhQukpMt1WErA0/nB+n7xRglRIP96CM 7PJlJGDpPwhQzMwNH1OJcbGrY9ffREyBMHfQBxIGMGdWACXV1cxQBVN5ij0BXk1XBYo1 DJAw+7Ez8DwTHo4zFdRKg3uguev8RYj2My1tF/iHBVr7f095by6TyMcHl97M4TCLNjNO /bQ2gJKcNPuOEaDus1xrmy1z1EplKD/wH2cyUifS2x1ki5aUbOr3KQmKVS738IZQH9Rk JHNnKywx/2TdAXtBJzIiKnJtpA6UkiqUB+L7qtjpTzU9fYSMuhCk47q3Sjci4Kw1m3Yi 7YJA== X-Gm-Message-State: AOJu0Yx0XZJO4nm3FaXNAv16pteUv/WsBpQiAtOGvvxt1eCxWpF+bvC/ DMmIZZrWnXSHmmPtC14itN/4i+QPSRHu X-Google-Smtp-Source: AGHT+IExEy4MT1RlmnzZMLhm7/rDozk7wpxsAHnJrA5Qq1I4GYy529PiD6cmwEWrK8tPiRiz9sjCDjHq9E9y X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a17:90b:2391:b0:27d:1cfb:7185 with SMTP id mr17-20020a17090b239100b0027d1cfb7185mr21475pjb.9.1697070294985; Wed, 11 Oct 2023 17:24:54 -0700 (PDT) Date: Wed, 11 Oct 2023 17:24:49 -0700 In-Reply-To: <20230930184821.310143-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230930184821.310143-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Message-ID: <20231012002451.254737-1-arakesh@google.com> Subject: [PATCH v4 1/3] usb: gadget: uvc: prevent use of disabled endpoint 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 X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Currently the set_alt callback immediately disables the endpoint and queues the v4l2 streamoff event. However, as the streamoff event is processed asynchronously, it is possible that the video_pump thread attempts to queue requests to an already disabled endpoint. This change moves disabling usb endpoint to the end of streamoff event callback. As the endpoint's state can no longer be used, video_pump is now guarded by uvc->state as well. To be consistent with the actual streaming state, uvc->state is now toggled between CONNECTED and STREAMING from the v4l2 event callback only. Link: https://lore.kernel.org/20230615171558.GK741@pendragon.ideasonboard.com/ Link: https://lore.kernel.org/20230531085544.253363-1-dan.scally@ideasonboard.com/ Reviewed-by: Michael Grzeschik Signed-off-by: Avichal Rakesh --- v1 -> v2: Rebased to ToT and reworded commit message. v2 -> v3: Fix email threading goof-up v3 -> v4: Address review comments & re-rebase to ToT drivers/usb/gadget/function/f_uvc.c | 11 +++++------ drivers/usb/gadget/function/f_uvc.h | 2 +- drivers/usb/gadget/function/uvc.h | 2 +- drivers/usb/gadget/function/uvc_v4l2.c | 21 ++++++++++++++++++--- drivers/usb/gadget/function/uvc_video.c | 3 ++- 5 files changed, 27 insertions(+), 12 deletions(-) -- 2.42.0.609.gbb76f46606-goog diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index faa398109431..ae08341961eb 100644 --- a/drivers/usb/gadget/function/f_uvc.c +++ b/drivers/usb/gadget/function/f_uvc.c @@ -263,10 +263,13 @@ uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) return 0; } -void uvc_function_setup_continue(struct uvc_device *uvc) +void uvc_function_setup_continue(struct uvc_device *uvc, int disable_ep) { struct usb_composite_dev *cdev = uvc->func.config->cdev; + if (disable_ep && uvc->video.ep) + usb_ep_disable(uvc->video.ep); + usb_composite_setup_continue(cdev); } @@ -337,15 +340,11 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt) if (uvc->state != UVC_STATE_STREAMING) return 0; - if (uvc->video.ep) - usb_ep_disable(uvc->video.ep); - memset(&v4l2_event, 0, sizeof(v4l2_event)); v4l2_event.type = UVC_EVENT_STREAMOFF; v4l2_event_queue(&uvc->vdev, &v4l2_event); - uvc->state = UVC_STATE_CONNECTED; - return 0; + return USB_GADGET_DELAYED_STATUS; case 1: if (uvc->state != UVC_STATE_CONNECTED) diff --git a/drivers/usb/gadget/function/f_uvc.h b/drivers/usb/gadget/function/f_uvc.h index 1db972d4beeb..e7f9f13f14dc 100644 --- a/drivers/usb/gadget/function/f_uvc.h +++ b/drivers/usb/gadget/function/f_uvc.h @@ -11,7 +11,7 @@ struct uvc_device; -void uvc_function_setup_continue(struct uvc_device *uvc); +void uvc_function_setup_continue(struct uvc_device *uvc, int disale_ep); void uvc_function_connect(struct uvc_device *uvc); diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 6751de8b63ad..989bc6b4e93d 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -177,7 +177,7 @@ struct uvc_file_handle { * Functions */ -extern void uvc_function_setup_continue(struct uvc_device *uvc); +extern void uvc_function_setup_continue(struct uvc_device *uvc, int disable_ep); extern void uvc_function_connect(struct uvc_device *uvc); extern void uvc_function_disconnect(struct uvc_device *uvc); diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index 3f0a9795c0d4..c0d77564a204 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -451,7 +451,7 @@ uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type) * Complete the alternate setting selection setup phase now that * userspace is ready to provide video frames. */ - uvc_function_setup_continue(uvc); + uvc_function_setup_continue(uvc, 0); uvc->state = UVC_STATE_STREAMING; return 0; @@ -463,11 +463,19 @@ uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type) struct video_device *vdev = video_devdata(file); struct uvc_device *uvc = video_get_drvdata(vdev); struct uvc_video *video = &uvc->video; + int ret = 0; if (type != video->queue.queue.type) return -EINVAL; - return uvcg_video_enable(video, 0); + uvc->state = UVC_STATE_CONNECTED; + ret = uvcg_video_enable(video, 0); + if (ret < 0) { + return ret; + } + + uvc_function_setup_continue(uvc, 1); + return 0; } static int @@ -500,6 +508,14 @@ uvc_v4l2_subscribe_event(struct v4l2_fh *fh, static void uvc_v4l2_disable(struct uvc_device *uvc) { uvc_function_disconnect(uvc); + /* + * Drop uvc->state to CONNECTED if it was streaming before. + * This ensures that the usb_requests are no longer queued + * to the controller. + */ + if (uvc->state == UVC_STATE_STREAMING) + uvc->state = UVC_STATE_CONNECTED; + uvcg_video_enable(&uvc->video, 0); uvcg_free_buffers(&uvc->video.queue); uvc->func_connected = false; @@ -647,4 +663,3 @@ const struct v4l2_file_operations uvc_v4l2_fops = { .get_unmapped_area = uvcg_v4l2_get_unmapped_area, #endif }; - diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 91af3b1ef0d4..c334802ac0a4 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -384,13 +384,14 @@ static void uvcg_video_pump(struct work_struct *work) struct uvc_video_queue *queue = &video->queue; /* video->max_payload_size is only set when using bulk transfer */ bool is_bulk = video->max_payload_size; + struct uvc_device *uvc = video->uvc; struct usb_request *req = NULL; struct uvc_buffer *buf; unsigned long flags; bool buf_done; int ret; - while (video->ep->enabled) { + while (uvc->state == UVC_STATE_STREAMING && video->ep->enabled) { /* * Retrieve the first available USB request, protected by the * request lock. From patchwork Thu Oct 12 00:24:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13418093 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E6D762A for ; Thu, 12 Oct 2023 00:25:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="paV3ju6q" Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CAB998 for ; Wed, 11 Oct 2023 17:24:58 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 41be03b00d2f7-563ab574cb5so272562a12.1 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=Slat/sHt0g7rwrIshfV2XiiUdS8wAMYQCrW+Z58hJITuIkeRnykSDbBbh2aJbTnVa8 Bh8JzBxs/kd7AMebwfOnyUMGVVOOUULKiWM0mLaXfXRowrULNojhdOrb7SNIe7sdvhv8 uB9fY+tWlTAzUu9eYYwVULOcgY2fRNXiAPke8etUGV8XEDL8Gjafa06xjwwaGvSpinL2 65HF2b0vJQrtbOjBhS1eTtjU651WVjX08FZQ1AByUzQg49hwWlXm6JXCZbNxkTpYH8gc tNOxPlaKNewYy4I2jJbokRm6oULw7BezLBYsfO7OjynaiWQfLammnZ1KdF5YNmx0aep4 VvwQ== X-Gm-Message-State: AOJu0YxjRCCEPamKLlNb0I3Q3j3DLXLzUUirbbDuPbcZADheJfbkLihW JXPqoqSEhIujBGjQPKNkmN9p2zq6Wbir 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> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net 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(-) -- 2.42.0.609.gbb76f46606-goog 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); From patchwork Thu Oct 12 00:24:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13418094 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C2EE62A for ; Thu, 12 Oct 2023 00:25:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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Wed, 11 Oct 2023 17:25:00 -0700 (PDT) Date: Wed, 11 Oct 2023 17:24:51 -0700 In-Reply-To: <20231012002451.254737-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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: <20231012002451.254737-3-arakesh@google.com> Subject: [PATCH v4 3/3] usb: gadget: uvc: Fix use-after-free for inflight usb_requests 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 X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net 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 is patch 2 of 2 in fixing the use-after-free issue. It adds a new flag to uvc_video to track when frames and requests should be flowing. When disabling the video stream, the flag is tripped and, instead of de-allocating all uvc_requests and usb_requests, the gadget driver only de-allocates those usb_requests that are currently owned by it (as present in req_free). Other usb_requests are left untouched until their completion handler is called which takes care of freeing the usb_request and its corresponding uvc_request. Now that uvc_video does not depends on uvc->state, this patch removes unnecessary upates to uvc->state that were made to accomodate uvc_video logic. This should ensure that uvc gadget driver never accidentally de-allocates a usb_request that it doesn't own. Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com Suggested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh Reviewed-by: Michael Grzeschik Tested-by: Michael Grzeschik --- v1 -> v2: Rebased to ToT, and fixed deadlock reported in https://lore.kernel.org/all/ZRv2UnKztgyqk2pt@pengutronix.de/ v2 -> v3: Fix email threading goof-up v3 -> v4: re-rebase to ToT & moved to a uvc_video level lock as discussed in https://lore.kernel.org/b14b296f-2e08-4edf-aeea-1c5b621e2d0c@google.com/ drivers/usb/gadget/function/uvc.h | 1 + drivers/usb/gadget/function/uvc_v4l2.c | 12 +- drivers/usb/gadget/function/uvc_video.c | 156 +++++++++++++++++++----- 3 files changed, 128 insertions(+), 41 deletions(-) -- 2.42.0.609.gbb76f46606-goog diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 993694da0bbc..be0d012aa244 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -102,6 +102,7 @@ struct uvc_video { unsigned int uvc_num_requests; /* Requests */ + bool is_enabled; /* tracks whether video stream is enabled */ unsigned int req_size; struct list_head ureqs; /* all uvc_requests allocated by uvc_video */ struct list_head req_free; diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index c0d77564a204..ded7d33c2a52 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -451,8 +451,8 @@ uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type) * Complete the alternate setting selection setup phase now that * userspace is ready to provide video frames. */ - uvc_function_setup_continue(uvc, 0); uvc->state = UVC_STATE_STREAMING; + uvc_function_setup_continue(uvc, 0); return 0; } @@ -468,12 +468,12 @@ uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type) if (type != video->queue.queue.type) return -EINVAL; - uvc->state = UVC_STATE_CONNECTED; ret = uvcg_video_enable(video, 0); if (ret < 0) { return ret; } + uvc->state = UVC_STATE_CONNECTED; uvc_function_setup_continue(uvc, 1); return 0; } @@ -508,14 +508,6 @@ uvc_v4l2_subscribe_event(struct v4l2_fh *fh, static void uvc_v4l2_disable(struct uvc_device *uvc) { uvc_function_disconnect(uvc); - /* - * Drop uvc->state to CONNECTED if it was streaming before. - * This ensures that the usb_requests are no longer queued - * to the controller. - */ - if (uvc->state == UVC_STATE_STREAMING) - uvc->state = UVC_STATE_CONNECTED; - uvcg_video_enable(&uvc->video, 0); uvcg_free_buffers(&uvc->video.queue); uvc->func_connected = false; diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index b62b3de79153..05b89b5b6c48 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -227,6 +227,9 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, * Request handling */ +/** + * Must be called with req_lock held as it modifies the list ureq is held in + */ static void uvc_video_free_request(struct uvc_request *ureq, struct usb_ep *ep) { @@ -271,9 +274,25 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) struct uvc_request *ureq = req->context; struct uvc_video *video = ureq->video; struct uvc_video_queue *queue = &video->queue; - struct uvc_device *uvc = video->uvc; + struct uvc_buffer *last_buf = NULL; unsigned long flags; + spin_lock_irqsave(&video->req_lock, flags); + if (!video->is_enabled) { + /* + * When is_enabled is false, uvc_video_disable ensures that + * in-flight uvc_buffers are returned, so we can safely + * call free_request without worrying about last_buf. + */ + uvc_video_free_request(ureq, ep); + spin_unlock_irqrestore(&video->req_lock, flags); + return; + } + + last_buf = ureq->last_buf; + ureq->last_buf = NULL; + spin_unlock_irqrestore(&video->req_lock, flags); + switch (req->status) { case 0: break; @@ -295,17 +314,26 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) uvcg_queue_cancel(queue, 0); } - if (ureq->last_buf) { - uvcg_complete_buffer(&video->queue, ureq->last_buf); - ureq->last_buf = NULL; + if (last_buf) { + spin_lock_irqsave(&queue->irqlock, flags); + uvcg_complete_buffer(&video->queue, last_buf); + spin_unlock_irqrestore(&queue->irqlock, flags); } spin_lock_irqsave(&video->req_lock, flags); - list_add_tail(&req->list, &video->req_free); - spin_unlock_irqrestore(&video->req_lock, flags); - - if (uvc->state == UVC_STATE_STREAMING) + /* + * Video stream might have been disabled while we were + * processing the current usb_request. So make sure + * we're still streaming before queueing the usb_request + * back to req_free + */ + if (video->is_enabled) { + list_add_tail(&req->list, &video->req_free); queue_work(video->async_wq, &video->pump); + } else { + uvc_video_free_request(ureq, ep); + } + spin_unlock_irqrestore(&video->req_lock, flags); } static int @@ -391,20 +419,22 @@ static void uvcg_video_pump(struct work_struct *work) struct uvc_video_queue *queue = &video->queue; /* video->max_payload_size is only set when using bulk transfer */ bool is_bulk = video->max_payload_size; - struct uvc_device *uvc = video->uvc; struct usb_request *req = NULL; struct uvc_buffer *buf; unsigned long flags; bool buf_done; int ret; - while (uvc->state == UVC_STATE_STREAMING && video->ep->enabled) { + while(true) { + if (!video->ep->enabled) + return; + /* - * Retrieve the first available USB request, protected by the - * request lock. + * Check is_enabled and retrieve the first available USB + * request, protected by the request lock. */ spin_lock_irqsave(&video->req_lock, flags); - if (list_empty(&video->req_free)) { + if (!video->is_enabled || list_empty(&video->req_free)) { spin_unlock_irqrestore(&video->req_lock, flags); return; } @@ -486,9 +516,78 @@ static void uvcg_video_pump(struct work_struct *work) return; spin_lock_irqsave(&video->req_lock, flags); - list_add_tail(&req->list, &video->req_free); + if (video->is_enabled) + list_add_tail(&req->list, &video->req_free); + else + uvc_video_free_request(req->context, video->ep); + spin_unlock_irqrestore(&video->req_lock, flags); +} + +/* + * Disable video stream + */ +static int +uvcg_video_disable(struct uvc_video *video) { + unsigned long flags; + struct list_head inflight_bufs; + struct usb_request *req, *temp; + struct uvc_buffer *buf, *btemp; + struct uvc_request *ureq, *utemp; + + INIT_LIST_HEAD(&inflight_bufs); + spin_lock_irqsave(&video->req_lock, flags); + video->is_enabled = false; + + /* + * Remove any in-flight buffers from the uvc_requests + * because we want to return them before cancelling the + * queue. This ensures that we aren't stuck waiting for + * all complete callbacks to come through before disabling + * vb2 queue. + */ + list_for_each_entry(ureq, &video->ureqs, list) { + if (ureq->last_buf) { + list_add_tail(&ureq->last_buf->queue, &inflight_bufs); + ureq->last_buf = NULL; + } + } spin_unlock_irqrestore(&video->req_lock, flags); - return; + + cancel_work_sync(&video->pump); + uvcg_queue_cancel(&video->queue, 0); + + spin_lock_irqsave(&video->req_lock, flags); + /* + * Remove all uvc_reqeusts from from ureqs with list_del_init + * This lets uvc_video_free_request correctly identify + * if the uvc_request is attached to a list or not when freeing + * memory. + */ + list_for_each_entry_safe(ureq, utemp, &video->ureqs, list) + list_del_init(&ureq->list); + + list_for_each_entry_safe(req, temp, &video->req_free, list) { + list_del(&req->list); + uvc_video_free_request(req->context, video->ep); + } + + INIT_LIST_HEAD(&video->ureqs); + INIT_LIST_HEAD(&video->req_free); + video->req_size = 0; + spin_unlock_irqrestore(&video->req_lock, flags); + + /* + * Return all the video buffers before disabling the queue. + */ + spin_lock_irqsave(&video->queue.irqlock, flags); + list_for_each_entry_safe(buf, btemp, &inflight_bufs, queue) { + list_del(&buf->queue); + uvcg_complete_buffer(&video->queue, buf); + } + spin_unlock_irqrestore(&video->queue.irqlock, flags); + + uvcg_queue_enable(&video->queue, 0); + return 0; } /* @@ -497,28 +596,22 @@ static void uvcg_video_pump(struct work_struct *work) int uvcg_video_enable(struct uvc_video *video, int enable) { int ret; - struct uvc_request *ureq; if (video->ep == NULL) { uvcg_info(&video->uvc->func, "Video enable failed, device is uninitialized.\n"); return -ENODEV; } - - if (!enable) { - cancel_work_sync(&video->pump); - uvcg_queue_cancel(&video->queue, 0); - - 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); - return 0; - } - + if (!enable) + return uvcg_video_disable(video); + + /* + * Safe to access request related fields without req_lock because + * this is the only thread currently active, and no other + * request handling thread will become active until this function + * returns. + */ + video->is_enabled = true; if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) return ret; @@ -544,6 +637,7 @@ int uvcg_video_enable(struct uvc_video *video, int enable) */ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) { + video->is_enabled = false; INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); spin_lock_init(&video->req_lock);