From patchwork Fri Oct 20 17:36:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13430985 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 89596200C7 for ; Fri, 20 Oct 2023 17:36:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="2OiBPOwe" Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7491A3 for ; Fri, 20 Oct 2023 10:36:30 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5a7d1816bccso14672267b3.1 for ; Fri, 20 Oct 2023 10:36:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697823390; x=1698428190; 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=i7TD3ZSccxCXhsCPFqExZCbB1Sg3nt/792JiPN6tc54=; b=2OiBPOweiTktKo+wkkYfXBF9sDPRNmpXrWD0Te6Ocu0Pr4dhCOR9dN//u1sXJUHtcm 9pZ8XrWTb2bDK7MMSCKdtMrysnOOkOw/4Fik7SCWUDecsfa+2A+HWP3kEZbPROFkTqqS zaQ0OA83TboVEqa7ATItxgCoMCQowcuU4p2UYGcN4H+BXsXCr/z30gvqeKp0FRJ9hRLO 6FFwvgkz80rqZO/IpJSJ+nGkg2llljirKVdg37H7M+kr2c/x7Z7HLPWbjVWQmBB0lwOD bN/Ez+JZSvexivYIPOEDoQrP/9x09q4ig0/fc1mEwHZsVLGo6Kuu4wPjZeXnwAI7ViNn O2fA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697823390; x=1698428190; 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=i7TD3ZSccxCXhsCPFqExZCbB1Sg3nt/792JiPN6tc54=; b=I5hTxzzcraALEmWKOg10EZGFvhX7r4Kh0NzTjsYpvDa8d+NccLT4hko5tV62fgo9k1 l60ZeAiyzaXFzSktAzUMe6Gr2VVtmUK5X0WCc6yvVBd0+RJdrA04qVtZud7VCD4AADJZ st/bPvGiS6299mDTJSy6mBrnOds8OXyP8VfU1OGUTl0+b9Nx6GAxyOa4D3WoGqJq3EcH OBENr59tDcDYJk7VwpDBscYWQwv8FWkPHdgFKb6M6OyRV4DVBS7koAImBT4WEb7Vjr3H J7PBlf79Gi9txMroeezSPCOQ8gXzU/WKYcu6cc8xKalPm+ukXf+HsSaGDN4t6qNp6KP0 mAzw== X-Gm-Message-State: AOJu0Yz4u8Yeim9Sf95l2SY7GumbgUyPzSoQW3dHEE09hCTAB3CCcJY8 0m+hi5y3GLsv9/JQrKACSk4Ah84c9b7u X-Google-Smtp-Source: AGHT+IHFtTIZ0AtY5+wFYLJXz74GXNoMgyHavvLZoCMakDX5ge5l55qAKKJlwPsTnOkJDPL2s5Yl5frnzP5J X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a25:bc90:0:b0:d9c:bdff:e45a with SMTP id e16-20020a25bc90000000b00d9cbdffe45amr48984ybk.12.1697823390090; Fri, 20 Oct 2023 10:36:30 -0700 (PDT) Date: Fri, 20 Oct 2023 10:36:23 -0700 In-Reply-To: <20231019185319.2714000-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231019185319.2714000-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Message-ID: <20231020173626.2978356-1-arakesh@google.com> Subject: [PATCH v7 1/4] usb: gadget: uvc: prevent use of disabled endpoint From: Avichal Rakesh To: arakesh@google.com, dan.scally@ideasonboard.com, laurent.pinchart@ideasonboard.com Cc: etalvala@google.com, gregkh@linuxfoundation.org, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, m.grzeschik@pengutronix.de 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 Tested-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 v4 -> v5: Add Reviewed-by & Tested-by v5 -> v6: No change v6 -> v7: No change 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 | 20 +++++++++++++++++--- drivers/usb/gadget/function/uvc_video.c | 3 ++- 5 files changed, 26 insertions(+), 12 deletions(-) -- 2.42.0.758.gaed0368e0e-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..7cb8d027ff0c 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 +463,18 @@ 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 +507,14 @@ 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 +662,3 @@ 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 Fri Oct 20 17:36:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13430986 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 7DE8C200C7 for ; Fri, 20 Oct 2023 17:36:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LzJt0LyR" Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE32211B for ; Fri, 20 Oct 2023 10:36:33 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d9cb79eb417so1274509276.2 for ; Fri, 20 Oct 2023 10:36:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697823393; x=1698428193; 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=cjsX2sP8PdwktlIcT7vwgRSFgChlueYzuoED2ZHB1eE=; b=LzJt0LyR0s1b0mZkBi3ddem+iIizoIVZ9Tfe38dNAQLjOXIPqLpFANtI885uBcSLPm RsKknRgRYD6p/eTWuTjAwy0CPLzK5lbUFa0gKHjf9j4yNby7tT2OkQ0lMuoNd58OkImr cqjqijjPRrxjxZ7cnU5zbl37guS7psYrr7BSHZf6b5cu1pBkVXTeN2uVpzDMKP26BEWJ a43KVwH801dOwBtI7B0D0OrMPaMr64O2m+c6f7Iswjxuno+2rwn+64TRKs7yx+knuGuH 3zJIU4aJYTUC7JeD7M8xxD6vEEOZck7IXC+XIzQJrSPdw/L8L1zt+4/+gj9Y7+Ae2g3u Exbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697823393; x=1698428193; 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=cjsX2sP8PdwktlIcT7vwgRSFgChlueYzuoED2ZHB1eE=; b=PIb/KiLwZfsbdfpb0GjCNbu69b/WswPsvNONvpDciPfETbPZq55XX3dq5xbJ4iMEyQ RV+tQWPOUDszwvgBSpKfwkk6Uy5C5OhZqme+fodGSMLJkp8B2f63Xc1xkrgjC340Ftgl +e/Jew8oQCSGZT1NJFezdgjtyul/1eHDX0eTheOGm4aLbZyd8Ba/C6Y4MdikgdymIEt4 7TSzwiN0ETbZeZnbYwcUqAbAv5egpJCTVjF97nIDEsT3Rdrb117n3I3hQ1sHJ5plVqpi cxt91znEwNVEUdYOlxtznzEUOwADObEHr/PtGEwcS9BTI3lkcgulKm2vTI/0MksJz28X 4h0A== X-Gm-Message-State: AOJu0Yy7eVyRdBhoIxRvXKmjBR6tVCdEy0HMbv3UDuEz3m4gYEMVe20t 88c2DVpDa9vObOClK0NjG7suqfBVwfzt X-Google-Smtp-Source: AGHT+IFYXzzdYjUhdB/4IxuitEybt6HvJ7PZHxWRuPf5s25LVKBN6UL4OybLwrpEs543974PWbCtT1o+JBSm X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a5b:b06:0:b0:d9a:3a26:fb56 with SMTP id z6-20020a5b0b06000000b00d9a3a26fb56mr53474ybp.2.1697823393235; Fri, 20 Oct 2023 10:36:33 -0700 (PDT) Date: Fri, 20 Oct 2023 10:36:24 -0700 In-Reply-To: <20231020173626.2978356-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231019185319.2714000-1-arakesh@google.com> <20231020173626.2978356-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Message-ID: <20231020173626.2978356-2-arakesh@google.com> Subject: [PATCH v7 2/4] 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 Cc: etalvala@google.com, gregkh@linuxfoundation.org, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, m.grzeschik@pengutronix.de 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 Tested-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 v4 -> v5: Address more review comments. Add Reviewed-by & Tested-by. v5 -> v6: No change v6 -> v7: No change drivers/usb/gadget/function/uvc.h | 3 +- drivers/usb/gadget/function/uvc_video.c | 89 ++++++++++++++----------- 2 files changed, 52 insertions(+), 40 deletions(-) -- 2.42.0.758.gaed0368e0e-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..c180866c8e34 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; - - if (video->ureq) { - for (i = 0; i < video->uvc_num_requests; ++i) { - sg_free_table(&video->ureq[i].sgt); + struct uvc_request *ureq, *temp; - 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 +336,34 @@ 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 +498,8 @@ 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 +511,10 @@ 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 +546,7 @@ 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); 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Fri, 20 Oct 2023 10:36:36 -0700 (PDT) Date: Fri, 20 Oct 2023 10:36:25 -0700 In-Reply-To: <20231020173626.2978356-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231019185319.2714000-1-arakesh@google.com> <20231020173626.2978356-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Message-ID: <20231020173626.2978356-3-arakesh@google.com> Subject: [PATCH v7 3/4] usb: gadget: uvc: move video disable logic to its own function From: Avichal Rakesh To: arakesh@google.com, dan.scally@ideasonboard.com, laurent.pinchart@ideasonboard.com Cc: etalvala@google.com, gregkh@linuxfoundation.org, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, m.grzeschik@pengutronix.de This patch refactors the video disable logic in uvcg_video_enable into its own separate function 'uvcg_video_disable'. Suggested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh --- v6: Introduced this patch to make the next one easier to review v6 -> v7: Add Suggested-by drivers/usb/gadget/function/uvc_video.c | 37 +++++++++++++++---------- 1 file changed, 23 insertions(+), 14 deletions(-) -- 2.42.0.758.gaed0368e0e-goog diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index c180866c8e34..80b8eaea2d39 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -493,13 +493,33 @@ static void uvcg_video_pump(struct work_struct *work) return; } +/* + * Disable video stream + */ +static int +uvcg_video_disable(struct uvc_video *video) +{ + struct uvc_request *ureq; + + 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; +} + /* * Enable or disable the video stream. */ 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, @@ -507,19 +527,8 @@ int uvcg_video_enable(struct uvc_video *video, int enable) 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); if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) return ret; From patchwork Fri Oct 20 17:36:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13430988 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 46ACA20324 for ; 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Fri, 20 Oct 2023 10:36:39 -0700 (PDT) Date: Fri, 20 Oct 2023 10:36:26 -0700 In-Reply-To: <20231020173626.2978356-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231019185319.2714000-1-arakesh@google.com> <20231020173626.2978356-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Message-ID: <20231020173626.2978356-4-arakesh@google.com> Subject: [PATCH v7 4/4] 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 Cc: etalvala@google.com, gregkh@linuxfoundation.org, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, m.grzeschik@pengutronix.de 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 accommodate 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 Reviewed-by: Michael Grzeschik Tested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh --- 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/ v4 -> v5: Address review comments. Add Reviewed-by & Tested-by. v5 -> v6: Added another patch before this one to make uvcg_video_disable easier to review. v6 -> v7: Fix warning reported in https://lore.kernel.org/202310200457.GwPPFuHX-lkp@intel.com/ drivers/usb/gadget/function/uvc.h | 1 + drivers/usb/gadget/function/uvc_v4l2.c | 12 +-- drivers/usb/gadget/function/uvc_video.c | 128 ++++++++++++++++++++---- 3 files changed, 111 insertions(+), 30 deletions(-) -- 2.42.0.758.gaed0368e0e-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 7cb8d027ff0c..f4d2e24835d4 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; } @@ -468,11 +468,11 @@ 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; } @@ -507,14 +507,6 @@ 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 80b8eaea2d39..ab3f02054e85 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 @@ -393,20 +421,22 @@ 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; } @@ -488,9 +518,11 @@ 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); - return; } /* @@ -499,17 +531,64 @@ static void uvcg_video_pump(struct work_struct *work) static int uvcg_video_disable(struct uvc_video *video) { - struct uvc_request *ureq; + 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); 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); + spin_lock_irqsave(&video->req_lock, flags); + /* + * Remove all uvc_reqeusts 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); } - uvc_video_free_requests(video); + 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; } @@ -530,6 +609,14 @@ int uvcg_video_enable(struct uvc_video *video, int enable) 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; @@ -555,6 +642,7 @@ 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);