From nobody Thu Jan 8 07:38:48 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A374E71D55 for ; Sat, 30 Sep 2023 18:48:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234745AbjI3Ssj (ORCPT ); Sat, 30 Sep 2023 14:48:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234734AbjI3Ssh (ORCPT ); Sat, 30 Sep 2023 14:48:37 -0400 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 070AAD3 for ; Sat, 30 Sep 2023 11:48:35 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 41be03b00d2f7-5803b6fadceso11936399a12.0 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=M//TJdlyo0Bjeix1Leosx0VYx3NNKwl8I2E6PEMbPCeF1noase+IxZn2xr2iHFb7YT wljjAzH4PaY9Tzrf+W4jAxIKD2G4TLzwOmZNvq2zicjgnL8WIvrX3gos67PZ4783FHxw 4OWbBsbVhd8EZ2TUkIxYNGuKwvuxDPO6MFL8IxrStKTDmu28Q1g5dKSCbE4xhzRgRqnc XUX8DhsqTRjnHqZ76KBYd4CmXj3sTR5FwEPtH7Z4YtxqyfhskLGq0lD5Hsn+dzoCP9Vb q75/zkV2ki/PkdWC12gLYSBipMsXMk0EdMteXsSdo0aiVDM8VKUu+zvl6MiWrqZmY43B P5PQ== X-Gm-Message-State: AOJu0Yzo115DT3kcwcYFQlqk6jUgaoW2NxnzlV2YlaLvTTdYyRfzJRlZ Jbgmf+QM1Fd0mgKRuafAfGWSHnpJhxmo 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> 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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.c= om 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/functio= n/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; }; =20 struct uvc_video { @@ -102,7 +103,7 @@ struct uvc_video { =20 /* 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; =20 diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/f= unction/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 */ =20 +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 =3D NULL; + } + + kfree(ureq->req_buffer); + ureq->req_buffer =3D 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_requ= est *req) static int uvc_video_free_requests(struct uvc_video *video) { - unsigned int i; - - if (video->ureq) { - for (i =3D 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 =3D NULL; - } + struct uvc_request *ureq, *temp; =20 - if (video->ureq[i].req_buffer) { - kfree(video->ureq[i].req_buffer); - video->ureq[i].req_buffer =3D NULL; - } - } - - kfree(video->ureq); - video->ureq =3D NULL; + list_for_each_entry_safe(ureq, temp, &video->ureqs, list) { + uvc_video_free_request(ureq, video->ep); } =20 + INIT_LIST_HEAD(&video->ureqs); INIT_LIST_HEAD(&video->req_free); video->req_size =3D 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 =3D -ENOMEM; @@ -332,29 +336,31 @@ uvc_video_alloc_requests(struct uvc_video *video) * max_t(unsigned int, video->ep->maxburst, 1) * (video->ep->mult); =20 - video->ureq =3D kcalloc(video->uvc_num_requests, sizeof(struct uvc_reques= t), GFP_KERNEL); - if (video->ureq =3D=3D NULL) - return -ENOMEM; - - for (i =3D 0; i < video->uvc_num_requests; ++i) { - video->ureq[i].req_buffer =3D kmalloc(req_size, GFP_KERNEL); - if (video->ureq[i].req_buffer =3D=3D NULL) + INIT_LIST_HEAD(&video->ureqs); + for (i =3D 0; i < video->uvc_num_requests; i++) { + ureq =3D kzalloc(sizeof(struct uvc_request), GFP_KERNEL); + if (ureq =3D=3D NULL) goto error; + INIT_LIST_HEAD(&ureq->list); + list_add_tail(&ureq->list, &video->ureqs); + } =20 - video->ureq[i].req =3D usb_ep_alloc_request(video->ep, GFP_KERNEL); - if (video->ureq[i].req =3D=3D NULL) + list_for_each_entry(ureq, &video->ureqs, list) { + ureq->req_buffer =3D kmalloc(req_size, GFP_KERNEL); + if (ureq->req_buffer =3D=3D NULL) goto error; - - video->ureq[i].req->buf =3D video->ureq[i].req_buffer; - video->ureq[i].req->length =3D 0; - video->ureq[i].req->complete =3D uvc_video_complete; - video->ureq[i].req->context =3D &video->ureq[i]; - video->ureq[i].video =3D video; - video->ureq[i].last_buf =3D NULL; - - list_add_tail(&video->ureq[i].req->list, &video->req_free); + ureq->req =3D usb_ep_alloc_request(video->ep, GFP_KERNEL); + if (ureq->req =3D=3D NULL) + goto error; + ureq->req->buf =3D ureq->req_buffer; + ureq->req->length =3D 0; + ureq->req->complete =3D uvc_video_complete; + ureq->req->context =3D ureq; + ureq->video =3D video; + ureq->last_buf =3D 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; =20 if (video->ep =3D=3D NULL) { uvcg_info(&video->uvc->func, @@ -502,9 +508,10 @@ int uvcg_video_enable(struct uvc_video *video, int ena= ble) cancel_work_sync(&video->pump); uvcg_queue_cancel(&video->queue, 0); =20 - for (i =3D 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); + } =20 uvc_video_free_requests(video); uvcg_queue_enable(&video->queue, 0); @@ -536,6 +543,7 @@ int uvcg_video_enable(struct uvc_video *video, int enab= le) */ 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); --=20 2.42.0.582.g8ccd20d70d-goog