linux-kernel - Re: [PATCH] usb: dwc3: qcom: fix NULL pointer dereference on dwc3_qcom_read_usb2

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240814001739.ml6czxo6ok67pihz@synopsys.com>
Date: Wed, 14 Aug 2024 00:17:46 +0000
From: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
To: Faisal Hassan <quic_faisalh@...cinc.com>
CC: Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: Re: [PATCH] usb: dwc3: qcom: fix NULL pointer dereference on
 dwc3_qcom_read_usb2_speed

On Tue, Aug 13, 2024, Faisal Hassan wrote:
> Null pointer dereference occurs when accessing 'hcd' to detect speed
> from dwc3_qcom_suspend after the xhci-hcd is unbound.
> To avoid this issue, ensure to check for NULL in dwc3_qcom_read_usb2_speed.
> 
> echo xhci-hcd.0.auto > /sys/bus/platform/drivers/xhci-hcd/unbind
>   xhci_plat_remove() -> usb_put_hcd() -> hcd_release() -> kfree(hcd)
> 
>   Unable to handle kernel NULL pointer dereference at virtual address
>   0000000000000060
>   Call trace:
>    dwc3_qcom_suspend.part.0+0x17c/0x2d0 [dwc3_qcom]
>    dwc3_qcom_runtime_suspend+0x2c/0x40 [dwc3_qcom]
>    pm_generic_runtime_suspend+0x30/0x44
>    __rpm_callback+0x4c/0x190
>    rpm_callback+0x6c/0x80
>    rpm_suspend+0x10c/0x620
>    pm_runtime_work+0xc8/0xe0
>    process_one_work+0x1e4/0x4f4
>    worker_thread+0x64/0x43c
>    kthread+0xec/0x100
>    ret_from_fork+0x10/0x20
> 
> Fixes: c5f14abeb52b ("usb: dwc3: qcom: fix peripheral and OTG suspend")
> Cc: stable@...r.kernel.org
> Signed-off-by: Faisal Hassan <quic_faisalh@...cinc.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 88fb6706a18d..0c7846478655 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -319,13 +319,15 @@ static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
>  static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom, int port_index)
>  {
>  	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);

What if dwc is not available?

> -	struct usb_device *udev;
> +	struct usb_device __maybe_unused *udev;

This is odd.... Is there a scenario where you don't want to set
CONFIG_USB if dwc3_qcom is in use?

>  	struct usb_hcd __maybe_unused *hcd;
>  
>  	/*
>  	 * FIXME: Fix this layering violation.
>  	 */
>  	hcd = platform_get_drvdata(dwc->xhci);
> +	if (!hcd)
> +		return USB_SPEED_UNKNOWN;
>  
>  #ifdef CONFIG_USB

Perhaps this #ifdef shouldn't only be checking this. But that's for
another patch.

>  	udev = usb_hub_find_child(hcd->self.root_hub, port_index + 1);
> -- 
> 2.17.1
> 

BR,
Thinh