From patchwork Thu Nov 9 00:41:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avichal Rakesh X-Patchwork-Id: 13450574 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 DBCBB62F for ; Thu, 9 Nov 2023 00:41:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="v5DAdgU1" 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 576D12695 for ; Wed, 8 Nov 2023 16:41:11 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-da0c6d62ec8so402775276.1 for ; Wed, 08 Nov 2023 16:41:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1699490470; x=1700095270; 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=fh1oz3TAY8GrHLzG/5dv3FTO7Esd6spc2LTiYNE8yAU=; b=v5DAdgU1xNffarArUedEvLuBwr0eAUipFuPqlFMoh0jhghRJ0RvhJi8Oyg9VXozym0 T2i4Sk6FatsQ0EDxQpH6wcUPo6NRTk0Lw/FIbskVDhaVXAWWLMJ5lMYuE80aorZgtijv rT/yaS658Ccor4nzee4T/OAS4gqAxU36+mFaKc4mePrIEdCi9qyUG/TgDyFNQxSM3jJe dGzALj2XEbqQY1H8NRI3Hw8bRzI8OHxLIUd+3AVLUkX0YNM+EXuXnhJVHUdePrckqKXv sliLjkb1ElKi4OI0gxzJSNA6L8VhtAgrefzvXLK10Z7FeKacVIzTNJM2jE9FGPyQIUcB Mxsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699490470; x=1700095270; 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=fh1oz3TAY8GrHLzG/5dv3FTO7Esd6spc2LTiYNE8yAU=; b=Kl/tv3mUbYWn3lfZ5m1VWBRmkA+yC3bpSpN2XlW2W+rNYzAHVml+Q0iuphJ+HFKW9f 8zR7/klQlfRJgOPMmFN6W3mfVnEI3MdiuyAV7cAva+eBrGZEU+mztqsRC+oxpb4g80Wj avAAktcAD0hE3nCVBTeBCeXxGDd4xJNMCfY3f8HjtTBcsLH8GoTE+H1oFDzcGztX9eV+ JPauJmAB0uPh9b6RRWEBptXAMoTohEfK2XnbW00550QcUmEmU0Hwhr+mkCUkSmzx67u6 5UOJErEa/URMgGuBvI+NOumfk65xKQ4DQKVrH7Pa2hDQhQQdajnCqJIwzq1puZaMr9B3 OYyw== X-Gm-Message-State: AOJu0Yz0XGLZo8OBF7NAD+Pfp8QzOCzvhdWShLuRESwY06i/Kb2ihHbI ygVm96H0GbMlguNG5EfYy0SpD+ihPuo2 X-Google-Smtp-Source: AGHT+IHiUEiFM/CnqNhZc9WGrQ5sha38ijbZD8SnXdOMYuZWk6hqYp7FSxicbfbvwjxHp/8e6AjHEdcVx8bI X-Received: from hi-h2o-specialist.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3cef]) (user=arakesh job=sendgmr) by 2002:a25:417:0:b0:da0:4f83:60c1 with SMTP id 23-20020a250417000000b00da04f8360c1mr81759ybe.9.1699490470624; Wed, 08 Nov 2023 16:41:10 -0800 (PST) Date: Wed, 8 Nov 2023 16:41:02 -0800 In-Reply-To: <20231109004104.3467968-1-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <73309396-3856-43a2-9a6f-81a40ed594db@google.com> <20231109004104.3467968-1-arakesh@google.com> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog Message-ID: <20231109004104.3467968-2-arakesh@google.com> Subject: [PATCH v12 2/4] usb: gadget: uvc: Allocate uvc_requests one at a time From: Avichal Rakesh To: arakesh@google.com, dan.scally@ideasonboard.com, gregkh@linuxfoundation.org Cc: etalvala@google.com, jchowdhary@google.com, laurent.pinchart@ideasonboard.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 Reviewed-by: Daniel Scally Reviewed-by: Michael Grzeschik Suggested-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 v7 -> v8 : No change. Getting back in review queue v8 -> v9 : Address review comments. v9 -> v10 : Address review comments; remove BUG_ON(&video->reqs); Rebase to ToT (usb-next) v10 -> v11 : Add Reviewed-by v11 -> v12 : Rebase to ToT (usb-next) drivers/usb/gadget/function/uvc.h | 3 +- drivers/usb/gadget/function/uvc_video.c | 88 ++++++++++++++----------- 2 files changed, 51 insertions(+), 40 deletions(-) -- 2.42.0.869.gea05f2083d-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..1619f9664748 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 +336,33 @@ 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++) { + 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 +497,8 @@ 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 +510,10 @@ 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 +545,7 @@ 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);