From patchwork Sat Sep 30 18:48:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13405186 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 4E71E138E for ; Sat, 30 Sep 2023 18:48:33 +0000 (UTC) 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 C7FFFE1 for ; Sat, 30 Sep 2023 11:48:31 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-59f8188b718so192531157b3.1 for ; Sat, 30 Sep 2023 11:48:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696099711; x=1696704511; 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=yVUNhv8Ca4Bneo2huWLmhKm4bUNhRAbGx7sDL56KZmE=; b=dn3jzL6UBvfdgT9ODHHBwGjuRi5jo/Qg9SAmRMCPoND7jdzfrDXUxpBRezyUyO1OGI pkPxAWPoiNYTz4t+mFpUvxLz245ILtM3OdO6r8HBAkA1zuYmJBHuS+DrXJUC6jPh/CcJ LuiEI3eQMvq1DvQtTvpIxAByi2LuAqHG5yiDf8MHGrWAaRMksEnEvn5GbEsq8jh8hDNf ffc6w0ZSBEGoKXUNF3NdQ1YlVzCDDWJlC8kuFhtiBd9CWIwjXq1mXPzdSZ6kojZJTaWU PvUI9V53D1qfcG2bHodz3kjKsUSOcark9mvPOpUSU28tO3THWnEkqlCpaQMTaWHeXnyM buvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696099711; x=1696704511; 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=yVUNhv8Ca4Bneo2huWLmhKm4bUNhRAbGx7sDL56KZmE=; b=cDeVfvcYuTgLRBnwFW0Axd3KUafH5Br5fGfCDTUVoJGQwonTP1Wh0fSHrr1HeeLLOF 45gABpN7/vaES+FtwSpgqR7uGB8Yd5fUnDhfqCuyp5cD79DmnB4aVdKjPysscdjtkOZy u8uveatRBly+KimWX5SOAmvWxNg8DlrZgQST7j9SPVUjaV2HDgSRRvrkXXQNQU8Xj3vg o94NSiqA+lg4OC1MlwQDXI8FhNy3XU55UdRMH4gNSlPd4AC220y0iHaMG3AWeGiPh4ZP 4pmI3uFMLrZxZd5LaZujFCAn9LoFRicFssXpAzBbxUzzjoIQCAwtgn6YRry5pmaPsc07 IhUg== X-Gm-Message-State: AOJu0YwDhXPGht0X1sQuQA7/KcKMXDEtJ4V0DN3TGV1nCrXfw8++tAWi xPtwYNTKAyNMhG5kUl8WyWit4RVVEC+o X-Google-Smtp-Source: AGHT+IH2JL4Oo3hXmwpi/7cv9ZKyYjENj1pnLNMUL0gqAEOjFbEGxjST1e6xqKTlnkxrjBsDeJB818mCYTdt X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a25:6f82:0:b0:d81:43c7:61ed with SMTP id k124-20020a256f82000000b00d8143c761edmr121329ybc.5.1696099711011; Sat, 30 Sep 2023 11:48:31 -0700 (PDT) Date: Sat, 30 Sep 2023 11:48:19 -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 2.42.0.582.g8ccd20d70d-goog Message-ID: <20230930184821.310143-2-arakesh@google.com> Subject: [PATCH v1 1/3] usb: gadget: uvc: prevent use of disabled endpoint From: Avichal Rakesh To: Laurent Pinchart , Daniel Scally , Greg Kroah-Hartman , Michael Grzeschik Cc: jchowdhary@google.com, etalvala@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Avichal Rakesh 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 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/ Signed-off-by: Avichal Rakesh --- 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(-) diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index faa398109431..75c9f9a3f884 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..3d3469883ed0 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); + if (uvc->state == UVC_STATE_STREAMING) { + /* + * Drop uvc->state to CONNECTED if it was streaming before. + * This ensures that the usb_requests are no longer queued + * to the controller. + */ + 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..70ff88854539 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -382,6 +382,7 @@ static void uvcg_video_pump(struct work_struct *work) { struct uvc_video *video = container_of(work, struct uvc_video, pump); struct uvc_video_queue *queue = &video->queue; + struct uvc_device *uvc = video->uvc; /* video->max_payload_size is only set when using bulk transfer */ bool is_bulk = video->max_payload_size; struct usb_request *req = NULL; @@ -390,7 +391,7 @@ static void uvcg_video_pump(struct work_struct *work) 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 Sat Sep 30 18:48:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13405187 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 E11B817728 for ; Sat, 30 Sep 2023 18:48:36 +0000 (UTC) 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 07BD5E1 for ; Sat, 30 Sep 2023 11:48:35 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 41be03b00d2f7-56f75e70190so14859050a12.3 for ; Sat, 30 Sep 2023 11:48:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696099714; x=1696704514; 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=mAs460jPiMP8R4cGJH03uN3F+PMNEKWmOscua1DAK48=; b=Y6pweDJp4Qn1rPKAL66slcaJGYTwDBvuqU9PMwSH+hgkZuVHqyrDsa/ur0RQyQe/O8 D7kG8M8FpIbYe2crnJpN9V3HOmZzZFaC4s6J/g/ORjGG3F/Sfubj40snFA0UEzZyRWWN 8nYgmhTsnj6HO4r6dgzeLEoBW0pJ3g0mUJwdNaWIu6tW/M55fDjNqbNPog73ReSbD/AP 3oXvUtCVEppxjw2CENX4huGGDrNT39nUU0QtPuraEEFKzLx4h7IE0RQyKhy7a3PBK2ha plmLTLoVaqCYMh7ouUq+nyjYnHKyjriJQIw6fYCwsbIlJdDakLmSNjMjK5qVLUyGmTMO 553g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696099714; x=1696704514; 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=mAs460jPiMP8R4cGJH03uN3F+PMNEKWmOscua1DAK48=; b=wPDwk7PXFDm9wUyOEtXw4W4QkDRzyxTvsFDhsYl6MWh00jSKt6eMtCxG5vVcg73o2c k/hUa+HhHzB1EKejzpjp8gplknCO0McYxEJ8K1fPupSTHhZe+0bjq532kd3VPqpqKqbf xsccPpkiOlsxtjM3SalDb3jVQdlv6byDxWP33KG6MuvPLLsch6ih2iF0wHiOGpZtneqW vp156GWubHq949V7atNQanK/AIQatYy7iXX3Zf1te8XobMEEDcL+chs0bc3bo2io9Ppl lxySB8Ahdo3DjYUpJ1QNOOXW6Zm7p8mFRV854w3SCpxVRkeZ/tid0oBlARur6PQIlrSW qsOw== X-Gm-Message-State: AOJu0YzHeRaB9pKNmwlcYDulBHtww6OgFjoPEUW4ioit78AR6F4AA7Fa ec1YOq8LfTy76fYA4bJmsT97d5X6oqN8 X-Google-Smtp-Source: AGHT+IGmIf/Hih00Q1XGFIl1z5z8HHKIzTAAmlYv2pxIx8tAIAj4qLz8C06N20kEcWtkUip+2fmYUhZsDkON X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a63:3649:0:b0:56f:8ff0:d164 with SMTP id d70-20020a633649000000b0056f8ff0d164mr114801pga.2.1696099714278; Sat, 30 Sep 2023 11:48:34 -0700 (PDT) Date: Sat, 30 Sep 2023 11:48:20 -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 2.42.0.582.g8ccd20d70d-goog Message-ID: <20230930184821.310143-3-arakesh@google.com> Subject: [PATCH v1 2/3] usb: gadget: uvc: Allocate uvc_requests one at a time From: Avichal Rakesh To: Laurent Pinchart , Daniel Scally , Greg Kroah-Hartman , Michael Grzeschik Cc: jchowdhary@google.com, etalvala@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Avichal Rakesh , Michael Grzeschik 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 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 Signed-off-by: Avichal Rakesh --- drivers/usb/gadget/function/uvc.h | 3 +- drivers/usb/gadget/function/uvc_video.c | 90 ++++++++++++++----------- 2 files changed, 51 insertions(+), 42 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 70ff88854539..ffecd7a140dc 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -227,6 +227,23 @@ 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 +310,13 @@ 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); - - if (video->ureq[i].req) { - usb_ep_free_request(video->ep, video->ureq[i].req); - video->ureq[i].req = NULL; - } + struct uvc_request *ureq, *temp; - 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 +336,31 @@ 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; - - 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) + 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); + } - video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); - if (video->ureq[i].req == NULL) + list_for_each_entry(ureq, &video->ureqs, list) { + ureq->req_buffer = kmalloc(req_size, GFP_KERNEL); + if (ureq->req_buffer == 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; - - list_add_tail(&video->ureq[i].req->list, &video->req_free); + ureq->req = usb_ep_alloc_request(video->ep, GFP_KERNEL); + if (ureq->req == NULL) + goto error; + 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(&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 +495,8 @@ 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 +508,10 @@ 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 +543,7 @@ 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 Sat Sep 30 18:48:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13405188 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 99F5F14F76 for ; Sat, 30 Sep 2023 18:48:41 +0000 (UTC) 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 28E9ED3 for ; Sat, 30 Sep 2023 11:48:39 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-59f8040b2ffso196892097b3.3 for ; Sat, 30 Sep 2023 11:48:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696099718; x=1696704518; 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=8sS0/uaQLhAvse+d/NY7S3JtHJHgQXnCXFHZHAD5jYQ=; b=tRLc6bqBTUC+HjWpMuM+lJSzMX7JOeSi+5VjDfx965ORJh4k2dXGYvpooRLZTa5g2f o/6cYNB6pXGXw+DCQoQXyCxfrGz8oQW6bkTbAxP1rlO7l1cQp4i8L+NZ/Yl8u4FhG+WB Bkb4S9gRWR04NGOJMishgCr4Jbzi3OF+ePmmajq+efN53iurJvUIUVT1v6D11kKRP8nY RZl/4CP6Qlxfk5ZmiiPAs4s1hi6nG4lOhJq3YuctxnKiMqhL50tNTmRpTp5SJFO/2bhL RsDbJXpNVrmCElhY2PHGbGaP9tjPTVxBzJze0umhW8G+/omiQnNzZriw4XqCNxP1ybJW 2vmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696099718; x=1696704518; 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=8sS0/uaQLhAvse+d/NY7S3JtHJHgQXnCXFHZHAD5jYQ=; b=kazTD+iqvByAVMePGoSWG60oQOGdh08j439LXCiTStiSOce+/tnRk3LaKheS1tMcHO iQn3K7S56vZxJhU2VLAGSf6ucpmZLht4/aDz2TYcXwiHJ6lZUC2I72s+SfSOnsFJHjFF 19o8mGAzGNBjvH7h57/a3twRpsiy1j+xKypIFzIfAwBnpUxUpZXmtQWJLGhDJn+cuxwR HmHTufxKyH+DkTDU6VoFxHinXY3ayQG47NRgPj4y3TcYL8NNBfWkbK4h2NTIa2UDAFyC LOY0dRI3eYQpT3/zlz2ingNP2uM3fZQpveMpv75JNvkFOflP9ObHwyEhmqoaR5zXwI6r HUlA== X-Gm-Message-State: AOJu0YymjrvZ62jF96sZ/i9sivXJIIswQ0lj7Cv5ql6i+BaOjiWALkMX my5t6FGkZYH7jPl2rmGVpyfgdQVW86Ek X-Google-Smtp-Source: AGHT+IHWdhL5RAVxsyWTiI4/e6dqT9qBN4mYpBbtKdY2IFEu9Ctuxp7yzyHR+CXeMVVBwlqF+9X+xO7MZ7h0 X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a05:690c:3412:b0:579:f832:74b with SMTP id fn18-20020a05690c341200b00579f832074bmr130768ywb.10.1696099718241; Sat, 30 Sep 2023 11:48:38 -0700 (PDT) Date: Sat, 30 Sep 2023 11:48:21 -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 2.42.0.582.g8ccd20d70d-goog Message-ID: <20230930184821.310143-4-arakesh@google.com> Subject: [PATCH v1 3/3] usb: gadget: uvc: Fix use-after-free for inflight usb_requests From: Avichal Rakesh To: Laurent Pinchart , Daniel Scally , Greg Kroah-Hartman , Michael Grzeschik Cc: jchowdhary@google.com, etalvala@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Avichal Rakesh , Michael Grzeschik 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 is patch 2 of 2 in fixing the use-after-free issue. It adds a new flag to uvc_request to mark it as 'abandoned'. When disabling the video stream, instead of de-allocating all uvc_requests and usb_requests, the gadget driver only de-allocates those usb_requests that are currently owned by the gadget driver (as present in req_free). Other usb_requests have their corresponding 'is_abandoned' flag tripped, and the usb_requests complete handler takes care of freeing the usb_request and its corresponding uvc_request. 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 --- drivers/usb/gadget/function/uvc.h | 1 + drivers/usb/gadget/function/uvc_video.c | 106 ++++++++++++++++++++---- 2 files changed, 91 insertions(+), 16 deletions(-) diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 993694da0bbc..e69cfb7cced1 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -82,6 +82,7 @@ struct uvc_request { u8 header[UVCG_REQUEST_HEADER_LEN]; struct uvc_buffer *last_buf; struct list_head list; + bool is_abandoned; }; struct uvc_video { diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index ffecd7a140dc..aad7dcba46ee 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -271,7 +271,21 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) struct uvc_video *video = ureq->video; struct uvc_video_queue *queue = &video->queue; struct uvc_device *uvc = video->uvc; + struct uvc_buffer *last_buf; unsigned long flags; + bool is_abandoned; + + spin_lock_irqsave(&video->req_lock, flags); + is_abandoned = ureq->is_abandoned; + last_buf = ureq->last_buf; + ureq->last_buf = NULL; + spin_unlock_irqrestore(&video->req_lock, flags); + + if (is_abandoned) { + uvcg_dbg(&video->uvc->func, "Freeing abandoned usb_request\n"); + uvc_video_free_request(ureq, ep); + return; + } switch (req->status) { case 0: @@ -294,15 +308,29 @@ 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(&video->queue.irqlock, flags); + uvcg_complete_buffer(&video->queue, last_buf); + spin_unlock_irqrestore(&video->queue.irqlock, flags); } + /* + * request might have been abandoned while being processed. + * do a last minute check before queueing the request back. + */ spin_lock_irqsave(&video->req_lock, flags); - list_add_tail(&req->list, &video->req_free); + is_abandoned = ureq->is_abandoned; + if (!is_abandoned) + list_add_tail(&req->list, &video->req_free); spin_unlock_irqrestore(&video->req_lock, flags); + if (is_abandoned) { + uvcg_dbg(&video->uvc->func, + "usb_request abandoned mid-processing - freeing.\n"); + uvc_video_free_request(ureq, ep); + return; + } + if (uvc->state == UVC_STATE_STREAMING) queue_work(video->async_wq, &video->pump); } @@ -366,7 +394,6 @@ uvc_video_alloc_requests(struct uvc_video *video) } video->req_size = req_size; - return 0; error: @@ -490,13 +517,69 @@ static void uvcg_video_pump(struct work_struct *work) return; } +/* + * Disable video stream. This ensures that any inflight usb requests are marked + * for clean up and all video buffers are dropped before returning. + */ +static void uvcg_video_disable(struct uvc_video *video) +{ + struct uvc_buffer *buf, *tmp_buf; + struct uvc_request *ureq, *temp; + struct list_head buf_list; /* track in-flight video buffers */ + struct usb_request *req; + unsigned long flags; + + cancel_work_sync(&video->pump); + uvcg_queue_cancel(&video->queue, 0); + + INIT_LIST_HEAD(&buf_list); + spin_lock_irqsave(&video->req_lock, flags); + /* abandon all usb requests */ + list_for_each_entry_safe(ureq, temp, &video->ureqs, list) { + ureq->is_abandoned = true; + if (ureq->last_buf) { + list_add(&ureq->last_buf->queue, &buf_list); + ureq->last_buf = NULL; + } + list_del_init(&ureq->list); + if (ureq->req) + usb_ep_dequeue(video->ep, ureq->req); + } + /* + * re-add uvc_requests currently owned by the gadget to + * video->ureqs to be deallocated + */ + list_for_each_entry(req, &video->req_free, list) { + ureq = req->context; + list_add_tail(&ureq->list, &video->ureqs); + } + spin_unlock_irqrestore(&video->req_lock, flags); + + /* + * drop abandoned uvc_buffers, as the completion handler + * no longer will + */ + if (!list_empty(&buf_list)) { + spin_lock_irqsave(&video->queue.irqlock, flags); + list_for_each_entry_safe(buf, tmp_buf, + &buf_list, queue) { + video->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE; + uvcg_complete_buffer(&video->queue, buf); + list_del(&buf->queue); + } + spin_unlock_irqrestore(&video->queue.irqlock, flags); + } + + uvc_video_free_requests(video); + uvcg_queue_enable(&video->queue, 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, @@ -505,16 +588,7 @@ int uvcg_video_enable(struct uvc_video *video, int enable) } 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); + uvcg_video_disable(video); return 0; }