From patchwork Wed Dec 14 11:18:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Ribalda X-Patchwork-Id: 634054 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 9089FC001B2 for ; Wed, 14 Dec 2022 11:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238219AbiLNLTh (ORCPT ); Wed, 14 Dec 2022 06:19:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237675AbiLNLTf (ORCPT ); Wed, 14 Dec 2022 06:19:35 -0500 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F6EDBF73 for ; Wed, 14 Dec 2022 03:19:34 -0800 (PST) Received: by mail-ed1-x52c.google.com with SMTP id i15so22030446edf.2 for ; Wed, 14 Dec 2022 03:19:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:from:to:cc:subject:date:message-id:reply-to; bh=lqYgjYCLtE2L72f2b146yyEU5fSX4l3ikwaqnULXRG0=; b=f0EYB+ywMq2SM6zO7j7oZ3uOvWkhNO4jlumBwyFoHjwuVUSsiJiXoa2TpbC17+nkYK uxzBotuSY+bHUWkswz6FAWFxsSXjyX8sh+taY7Uml8nFUQ55m9mDmgVVIYz1WMiIKxJL jPbtAId/bcj7ajzqmOGP3vyenyn7bwLudb84A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=lqYgjYCLtE2L72f2b146yyEU5fSX4l3ikwaqnULXRG0=; b=tXsaH90UaH3ZUBXDwnjHSt+zRTGNAbm4yJMcIK0vPrwrAunaCm/mwLWMPcB6RoT59k tylsEDJeYfoQlHbfRn07fOvaFWXDVTsL4gBXTW8zX0kEtGc4KTCpSX+N9X+lYHoX7WHa 8opmdhFvX+/zpJs+78YmMcjZJSH1pRccoQQxtpxRwwHIqQq47f9XEFkWKSHpgzOWDX/+ odAW+rqamo542c95/uHcYg6T70devmqjvmTbItCLmsEx4cMkfMl6fKRV1F7t/ZxszLPl pjj34ZivCjrkgW3ASGdLerTvucFF2tGDlHrTCGu4z+uDmM6004lsGooHe1+RGV0/uHYD Q1+Q== X-Gm-Message-State: ANoB5pnzGLKNcTXhk5aG13GoDFV9m8CZd6q2GbK6msBS12VqPoReynFy 5GnPQGMrbO2AGfAaJVsDxOBltjUHfSDonxegA38= X-Google-Smtp-Source: AA0mqf5ZsE4ye8IFy5V1nxAjAHZzcR5UfBV/Jg6PsG+u4ZnFKrdEodZe44omLfRObw6S9EdXIk/IlQ== X-Received: by 2002:a05:6402:294f:b0:46c:e226:7717 with SMTP id ed15-20020a056402294f00b0046ce2267717mr22592544edb.31.1671016772906; Wed, 14 Dec 2022 03:19:32 -0800 (PST) Received: from alco.roam.corp.google.com ([100.104.168.209]) by smtp.gmail.com with ESMTPSA id s9-20020a508d09000000b00462e1d8e914sm6147842eds.68.2022.12.14.03.19.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Dec 2022 03:19:32 -0800 (PST) From: Ricardo Ribalda Date: Wed, 14 Dec 2022 12:18:52 +0100 Subject: [PATCH v3] media: uvcvideo: Fix race condition with usb_kill_urb MIME-Version: 1.0 Message-Id: <20221212-uvc-race-v3-0-954efc752c9a@chromium.org> To: Laurent Pinchart , Mauro Carvalho Chehab , Sergey Senozhatsky , Max Staudt Cc: Ricardo Ribalda , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Yunke Cao , stable@vger.kernel.org X-Mailer: b4 0.11.0-dev-696ae X-Developer-Signature: v=1; a=openpgp-sha256; l=4125; i=ribalda@chromium.org; h=from:subject:message-id; bh=fAcZ3Rb/oLvmz2WVeJpX5Jp809XzJo8lwMwPsv9AhLw=; b=owEBbQKS/ZANAwAKAdE30T7POsSIAcsmYgBjmbE38/EjSW7pYSQWBBTtxFS+gGqtW8i6Pd+83n94 5dsMscmJAjMEAAEKAB0WIQREDzjr+/4oCDLSsx7RN9E+zzrEiAUCY5mxNwAKCRDRN9E+zzrEiBzgD/ 91H1p8xDaegLuUzI3YejSZMVxB9xUPubBopI2ndm40hTN4UF3Z6F5uHCW0BokHZO59L6TcM8yOzGP9 xnPSd6ufmc48vZ78quyJuyKsSwMHOKaALfD8N88pJ16zP+Tcy/AD8Vo82zUxsjGiDzL6aVbNflfhG0 uGRd9k3w9qizGwKIvwcCtk6DgoO1oygIJGsRs4Mfg6QxeJ65kfsCA9mgpSl+2+sr3wnuUL1QnPbrNn BMSi81wxFc2sNoPX8xgbzpHbMR87R5/ydLqet+mFYEccvPIB67ubOHFrZPDnOUGngw4NCHKI+fVr9Y MNSjDt3ZHtuiWo8JWpSrYj4uBz5j+Jf5ChjJGdietXSTjGgXmI1G5Pi82C3EM4Y1U0QafnNvQsKi+Z L7iqDZmk2IfVwibvNEk7Lb8z8BDZoyiAzxBOaie1xpZ2+S3lUREoXL4DJMz+foGYrqk8R5H9rPOUZx py0u/3SEJOYdfxj/+fK6rvQPqtOgJMiApiOPDtODmi39hpokdJJdoDrS+DYQdF1du7HEl6bpbddPOs 981YY8r3d9TIxjqhs97sLeyt9xw3J9HmiufcFhP6AnWVeEy5c7NhAIP0eduO41p2EtP26fjKp2KxzY QyzkJkEru0PaSHQAZ8/dYdp24ijeEyzngqVzyaewnzRjOymGgsi7Ru3JLDPA== X-Developer-Key: i=ribalda@chromium.org; a=openpgp; fpr=9EC3BB66E2FC129A6F90B39556A0D81F9F782DA9 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org usb_kill_urb warranties that all the handlers are finished when it returns, but does not protect against threads that might be handling asynchronously the urb. For UVC, the function uvc_ctrl_status_event_async() takes care of control changes asynchronously. If the code is executed in the following order: CPU 0 CPU 1 ===== ===== uvc_status_complete() uvc_status_stop() uvc_ctrl_status_event_work() uvc_status_start() -> FAIL Then uvc_status_start will keep failing and this error will be shown: <4>[ 5.540139] URB 0000000000000000 submitted while active drivers/usb/core/urb.c:378 usb_submit_urb+0x4c3/0x528 Let's improve the current situation, by not re-submiting the urb if we are stopping the status event. Also process the queued work (if any) during stop. CPU 0 CPU 1 ===== ===== uvc_status_complete() uvc_status_stop() uvc_status_start() uvc_ctrl_status_event_work() -> FAIL Hopefully, with the usb layer protection this should be enough to cover all the cases. Cc: stable@vger.kernel.org Fixes: e5225c820c05 ("media: uvcvideo: Send a control event when a Control Change interrupt arrives") Reviewed-by: Yunke Cao Signed-off-by: Ricardo Ribalda --- uvc: Fix race condition on uvc Make sure that all the async work is finished when we stop the status urb. To: Yunke Cao To: Sergey Senozhatsky To: Max Staudt To: Laurent Pinchart To: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Changes in v3: - Remove the patch for dev->status, makes more sense in another series, and makes the zero day less nervous. - Update reviewed-by (thanks Yunke!). - Link to v2: https://lore.kernel.org/r/20221212-uvc-race-v2-0-54496cc3b8ab@chromium.org Changes in v2: - Add a patch for not kalloc dev->status - Redo the logic mechanism, so it also works with suspend (Thanks Yunke!) - Link to v1: https://lore.kernel.org/r/20221212-uvc-race-v1-0-c52e1783c31d@chromium.org --- drivers/media/usb/uvc/uvc_ctrl.c | 3 +++ drivers/media/usb/uvc/uvc_status.c | 6 ++++++ drivers/media/usb/uvc/uvcvideo.h | 1 + 3 files changed, 10 insertions(+) --- base-commit: 0ec5a38bf8499f403f81cb81a0e3a60887d1993c change-id: 20221212-uvc-race-09276ea68bf8 Best regards, diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index c95a2229f4fa..5160facc8e20 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1442,6 +1442,9 @@ static void uvc_ctrl_status_event_work(struct work_struct *work) uvc_ctrl_status_event(w->chain, w->ctrl, w->data); + if (dev->flush_status) + return; + /* Resubmit the URB. */ w->urb->interval = dev->int_ep->desc.bInterval; ret = usb_submit_urb(w->urb, GFP_KERNEL); diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c index 7518ffce22ed..09a5802dc974 100644 --- a/drivers/media/usb/uvc/uvc_status.c +++ b/drivers/media/usb/uvc/uvc_status.c @@ -304,10 +304,16 @@ int uvc_status_start(struct uvc_device *dev, gfp_t flags) if (dev->int_urb == NULL) return 0; + dev->flush_status = false; return usb_submit_urb(dev->int_urb, flags); } void uvc_status_stop(struct uvc_device *dev) { + struct uvc_ctrl_work *w = &dev->async_ctrl; + + dev->flush_status = true; usb_kill_urb(dev->int_urb); + if (cancel_work_sync(&w->work)) + uvc_ctrl_status_event(w->chain, w->ctrl, w->data); } diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h index df93db259312..6a9b72d6789e 100644 --- a/drivers/media/usb/uvc/uvcvideo.h +++ b/drivers/media/usb/uvc/uvcvideo.h @@ -560,6 +560,7 @@ struct uvc_device { struct usb_host_endpoint *int_ep; struct urb *int_urb; u8 *status; + bool flush_status; struct input_dev *input; char input_phys[64];