From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f43.google.com (mail-io1-f43.google.com [209.85.166.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C4BF17B022 for ; Tue, 9 Jul 2024 19:38:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720553892; cv=none; b=DDrX+IZZI12qNEVHNl3qwQu6+/ZbeixtR1WQrkHUYgzDzEEuIruqo7wjPItiRdroqQplU7vHe4dvaQ7Q0Mzm6aL2UKEjNWvzZWE/rGvj72217hz9lX9QATVWsylVzPTpfgsonKm2ravm6n7tCyhcInP/DEW/7/F1SCU3kXL6424= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720553892; c=relaxed/simple; bh=aZGDDnoMG/Df7JC21hST6E7KySxJtKeWyt3KgLdI294=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=keT7/38VWxR2FVp+GH7sCyDvtc4ngmjEcrpHa8HqLk0E2TQ+6z7BhbGKPVE7bYq56RruTZR2mOlfOZSg/1wkcuFX97Mt7dvNyPRBsdBfAPoLjJx3GTrJGfQ3q87pbbQiyv5rHXPJs46zaRAdSZLPX4kgkW9oALN1ttr8hw7T5JU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linuxfoundation.org; spf=pass smtp.mailfrom=linuxfoundation.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GTdzbt6D; arc=none smtp.client-ip=209.85.166.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linuxfoundation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GTdzbt6D" Received: by mail-io1-f43.google.com with SMTP id ca18e2360f4ac-7eb41831704so19668639f.1 for ; Tue, 09 Jul 2024 12:38:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=google; t=1720553888; x=1721158688; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=zm3hQRY8uz93xtaK2fqdUNltBkmPIjvamnTYb0ZY0Hs=; b=GTdzbt6D+qV+SJDDv5wlPaxIRsQLKO61GIEdwe0ieQ/T9gH9I8HDfTlo4oTP26fRzh WlLvK6P7BDrSBPTXMeH1NR+AvAAcGbzmF4ZV2tk3xMqx0Z9r8Pk1kmm2BmsPEP3DOaNB yepabAsJ3D1Nux8xmw0Ft0VLs7PTcdT5SNisw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720553888; x=1721158688; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=zm3hQRY8uz93xtaK2fqdUNltBkmPIjvamnTYb0ZY0Hs=; b=se0Y8IZIIvw7++XtT8Z9UWYIFa2mc6ynxxStgW+XMnmemjqkHpqtWwN5J4MLo+2Kpp U3A9CNX2NPSfihFlodu2NZSDUQvhYoA/jDMzI/PptQg3n4G45M+OKWBjEcNLAxwm544k 6tlcN2mA3oaNT/quNSTWjW+lQFUnCCAZtIHIBsNKgbPL6AspciCLTRZjH8u2nw7jDo3z 5j6mrSQnJ5WYdjKb+/tPU2fUDL+Sal2yyifeeohnKGADxsagmO9zq1d17xz9RL7YMyFS k71wkh6Gp40UeqVUocbs3G3ReFVIZA2LqoisfUQaboZE7GQ3okcseiNYi8L+XZX2tYNd khxA== X-Forwarded-Encrypted: i=1; AJvYcCUQqW24sA7zCde0SI7oFZ/9yhfjSGZzijgt1tsabHf1OumPGmlQmAle4ZeZNA8LQzyiMvlfNwLpVvgTpqG3iZmoOuL8Ii9+iZQR X-Gm-Message-State: AOJu0YyetVwcE81VQlRl4QcVTc/MKoXH4Wu5tinNcwhsYP3ngNd7RLdq I7TtuffM7KQDKH8Onb31ZGdsUzxvBabDgtueuiACwPQCHQgrwEJa3/VltRFfsDA= X-Google-Smtp-Source: AGHT+IFfA9QfY79FcqiyI75GsSWuHyTxtSwB04Ey+hrqJjwf+Gbv7BNuQnKKoIo+k/kumVQy2l+/Lw== X-Received: by 2002:a05:6602:3408:b0:7f9:3fd9:cbb with SMTP id ca18e2360f4ac-80001c0f1e8mr441610739f.1.1720553888233; Tue, 09 Jul 2024 12:38:08 -0700 (PDT) Received: from [192.168.1.128] ([38.175.170.29]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-7ffe9accc19sm70463439f.20.2024.07.09.12.38.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Jul 2024 12:38:07 -0700 (PDT) Message-ID: Date: Tue, 9 Jul 2024 13:38:07 -0600 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] usb: vhci-hcd: Do not drop references before new references are gained To: Oliver Neukum , valentina.manea.m@gmail.com, shuah@kernel.org, i@zenithal.me, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, Shuah Khan References: <20240709113851.14691-1-oneukum@suse.com> Content-Language: en-US From: Shuah Khan In-Reply-To: <20240709113851.14691-1-oneukum@suse.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/9/24 05:38, Oliver Neukum wrote: > At a few places the driver carries stale pointers > to references that can still be used. Make sure that does not happen. > This strictly speaking closes ZDI-CAN-22273, though there may be > similar races in the driver. > > Signed-off-by: Oliver Neukum Sorry I need a bit more explanation to follow the change you are making. Also how did you find the problem? > --- > drivers/usb/usbip/vhci_hcd.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c > index 82650c11e451..302a89aeb258 100644 > --- a/drivers/usb/usbip/vhci_hcd.c > +++ b/drivers/usb/usbip/vhci_hcd.c > @@ -745,6 +745,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag > * > */ > if (usb_pipedevice(urb->pipe) == 0) { > + struct usb_device *old; > __u8 type = usb_pipetype(urb->pipe); > struct usb_ctrlrequest *ctrlreq = > (struct usb_ctrlrequest *) urb->setup_packet; > @@ -755,14 +756,15 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag > goto no_need_xmit; > } > > + old = vdev->udev; > switch (ctrlreq->bRequest) { > case USB_REQ_SET_ADDRESS: > /* set_address may come when a device is reset */ > dev_info(dev, "SetAddress Request (%d) to port %d\n", > ctrlreq->wValue, vdev->rhport); > > - usb_put_dev(vdev->udev); > vdev->udev = usb_get_dev(urb->dev); > + usb_put_dev(old); > > spin_lock(&vdev->ud.lock); > vdev->ud.status = VDEV_ST_USED; > @@ -781,8 +783,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag > usbip_dbg_vhci_hc( > "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n"); > > - usb_put_dev(vdev->udev); > vdev->udev = usb_get_dev(urb->dev); > + usb_put_dev(old); > goto out; > > default: > @@ -1067,6 +1069,7 @@ static void vhci_shutdown_connection(struct usbip_device *ud) > static void vhci_device_reset(struct usbip_device *ud) > { > struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); > + struct usb_device *old = vdev->udev; > unsigned long flags; > > spin_lock_irqsave(&ud->lock, flags); > @@ -1074,8 +1077,8 @@ static void vhci_device_reset(struct usbip_device *ud) > vdev->speed = 0; > vdev->devid = 0; > > - usb_put_dev(vdev->udev); > vdev->udev = NULL; > + usb_put_dev(old); > > if (ud->tcp_socket) { > sockfd_put(ud->tcp_socket); thanks, -- Shuah