Re: [PATCH v2 3/9] ALSA: caiaq: Add a sanity check for invalid EPs

2017-10-11 Thread Johan Hovold 
On Wed, Oct 11, 2017 at 12:36:40PM +0200, Takashi Iwai wrote:
> As syzkaller spotted, currently caiaq driver submits a URB with the
> fixed EP without checking whether it's actually available, which may
> result in a kernel warning like:
>   usb 1-1: BOGUS urb xfer, pipe 3 != type 1
>   [ cut here ]
>   WARNING: CPU: 1 PID: 1150 at drivers/usb/core/urb.c:449
>   usb_submit_urb+0xf8a/0x11d0
>   Modules linked in:
>   CPU: 1 PID: 1150 Comm: kworker/1:1 Not tainted
>   4.14.0-rc2-42660-g24b7bd59eec0 #277
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Workqueue: usb_hub_wq hub_event
>   Call Trace:
>init_card sound/usb/caiaq/device.c:467
>snd_probe+0x81c/0x1150 sound/usb/caiaq/device.c:525
>usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
>
> 
> This patch adds a sanity check of validity of EPs at the device
> initialization phase for avoiding the call with an invalid EP.
> 
> Reported-by: Andrey Konovalov 
> Tested-by: Andrey Konovalov 
> Signed-off-by: Takashi Iwai 
> ---
>  sound/usb/caiaq/device.c | 7 +++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c
> index 0fb6b1b79261..a29674bf96e5 100644
> --- a/sound/usb/caiaq/device.c
> +++ b/sound/usb/caiaq/device.c
> @@ -461,6 +461,13 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
> cdev->midi_out_buf, EP1_BUFSIZE,
> snd_usb_caiaq_midi_output_done, cdev);
>  
> + /* sanity checks of EPs before actually submitting */
> + if (usb_urb_ep_type_check(&cdev->ep1_in_urb) ||
> + usb_urb_ep_type_check(&cdev->midi_out_urb)) {
> + dev_err(dev, "invalid EPs\n");
> + return -EINVAL;
> + }
> +

Unrelated to this patch, but this driver fails to kill the ep1_in_urb
(which is submitted in this function) in case of later probe errors.
This can lead to use-after-free or crashes in the completion callback.

>   init_waitqueue_head(&cdev->ep1_wait_queue);
>   init_waitqueue_head(&cdev->prepare_wait_queue);

Johan
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Re: [PATCH v2 3/9] ALSA: caiaq: Add a sanity check for invalid EPs

2017-10-11 Thread Takashi Iwai 
On Wed, 11 Oct 2017 16:20:31 +0200,
Johan Hovold wrote:
> 
> On Wed, Oct 11, 2017 at 12:36:40PM +0200, Takashi Iwai wrote:
> > As syzkaller spotted, currently caiaq driver submits a URB with the
> > fixed EP without checking whether it's actually available, which may
> > result in a kernel warning like:
> >   usb 1-1: BOGUS urb xfer, pipe 3 != type 1
> >   [ cut here ]
> >   WARNING: CPU: 1 PID: 1150 at drivers/usb/core/urb.c:449
> >   usb_submit_urb+0xf8a/0x11d0
> >   Modules linked in:
> >   CPU: 1 PID: 1150 Comm: kworker/1:1 Not tainted
> >   4.14.0-rc2-42660-g24b7bd59eec0 #277
> >   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 
> > 01/01/2011
> >   Workqueue: usb_hub_wq hub_event
> >   Call Trace:
> >init_card sound/usb/caiaq/device.c:467
> >snd_probe+0x81c/0x1150 sound/usb/caiaq/device.c:525
> >usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
> >
> > 
> > This patch adds a sanity check of validity of EPs at the device
> > initialization phase for avoiding the call with an invalid EP.
> > 
> > Reported-by: Andrey Konovalov 
> > Tested-by: Andrey Konovalov 
> > Signed-off-by: Takashi Iwai 
> > ---
> >  sound/usb/caiaq/device.c | 7 +++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c
> > index 0fb6b1b79261..a29674bf96e5 100644
> > --- a/sound/usb/caiaq/device.c
> > +++ b/sound/usb/caiaq/device.c
> > @@ -461,6 +461,13 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
> >   cdev->midi_out_buf, EP1_BUFSIZE,
> >   snd_usb_caiaq_midi_output_done, cdev);
> >  
> > +   /* sanity checks of EPs before actually submitting */
> > +   if (usb_urb_ep_type_check(&cdev->ep1_in_urb) ||
> > +   usb_urb_ep_type_check(&cdev->midi_out_urb)) {
> > +   dev_err(dev, "invalid EPs\n");
> > +   return -EINVAL;
> > +   }
> > +
> 
> Unrelated to this patch, but this driver fails to kill the ep1_in_urb
> (which is submitted in this function) in case of later probe errors.
> This can lead to use-after-free or crashes in the completion callback.

Yes, a good catch.  Below is the fix patch.


thanks,

Takashi

-- 8< --
From: Takashi Iwai 
Subject: [PATCH] ALSA: caiaq: Fix stray URB at probe error path

caiaq driver doesn't kill the URB properly at its error path during
the probe, which may lead to a use-after-free error later.  This patch
addresses it.

Reported-by: Johan Hovold 
Signed-off-by: Takashi Iwai 
---
 sound/usb/caiaq/device.c | 12 +---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c
index a29674bf96e5..d55ca48de3ea 100644
--- a/sound/usb/caiaq/device.c
+++ b/sound/usb/caiaq/device.c
@@ -476,10 +476,12 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
 
err = snd_usb_caiaq_send_command(cdev, EP1_CMD_GET_DEVICE_INFO, NULL, 
0);
if (err)
-   return err;
+   goto err_kill_urb;
 
-   if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ))
-   return -ENODEV;
+   if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ)) 
{
+   err = -ENODEV;
+   goto err_kill_urb;
+   }
 
usb_string(usb_dev, usb_dev->descriptor.iManufacturer,
   cdev->vendor_name, CAIAQ_USB_STR_LEN);
@@ -514,6 +516,10 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
 
setup_card(cdev);
return 0;
+
+ err_kill_urb:
+   usb_kill_urb(&cdev->ep1_in_urb);
+   return err;
 }
 
 static int snd_probe(struct usb_interface *intf,
-- 
2.14.2

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Re: [PATCH v2 3/9] ALSA: caiaq: Add a sanity check for invalid EPs

2017-10-11 Thread Johan Hovold 
On Wed, Oct 11, 2017 at 04:40:36PM +0200, Takashi Iwai wrote:
> On Wed, 11 Oct 2017 16:20:31 +0200,
> Johan Hovold wrote:

> > Unrelated to this patch, but this driver fails to kill the ep1_in_urb
> > (which is submitted in this function) in case of later probe errors.
> > This can lead to use-after-free or crashes in the completion callback.
> 
> Yes, a good catch.  Below is the fix patch.

> -- 8< --
> From: Takashi Iwai 
> Subject: [PATCH] ALSA: caiaq: Fix stray URB at probe error path
> 
> caiaq driver doesn't kill the URB properly at its error path during
> the probe, which may lead to a use-after-free error later.  This patch
> addresses it.
> 
> Reported-by: Johan Hovold 
> Signed-off-by: Takashi Iwai 

Looks good to me:

Reviewed-by: Johan Hovold 

> ---
>  sound/usb/caiaq/device.c | 12 +---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c
> index a29674bf96e5..d55ca48de3ea 100644
> --- a/sound/usb/caiaq/device.c
> +++ b/sound/usb/caiaq/device.c
> @@ -476,10 +476,12 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
>  
>   err = snd_usb_caiaq_send_command(cdev, EP1_CMD_GET_DEVICE_INFO, NULL, 
> 0);
>   if (err)
> - return err;
> + goto err_kill_urb;
>  
> - if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ))
> - return -ENODEV;
> + if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ)) 
> {
> + err = -ENODEV;
> + goto err_kill_urb;
> + }
>  
>   usb_string(usb_dev, usb_dev->descriptor.iManufacturer,
>  cdev->vendor_name, CAIAQ_USB_STR_LEN);
> @@ -514,6 +516,10 @@ static int init_card(struct snd_usb_caiaqdev *cdev)
>  
>   setup_card(cdev);
>   return 0;
> +
> + err_kill_urb:
> + usb_kill_urb(&cdev->ep1_in_urb);
> + return err;
>  }
>  
>  static int snd_probe(struct usb_interface *intf,
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Re: [PATCH v2 3/9] ALSA: caiaq: Add a sanity check for invalid EPs

2017-10-11 Thread Takashi Iwai 
On Wed, 11 Oct 2017 16:49:10 +0200,
Johan Hovold wrote:
> 
> On Wed, Oct 11, 2017 at 04:40:36PM +0200, Takashi Iwai wrote:
> > On Wed, 11 Oct 2017 16:20:31 +0200,
> > Johan Hovold wrote:
> 
> > > Unrelated to this patch, but this driver fails to kill the ep1_in_urb
> > > (which is submitted in this function) in case of later probe errors.
> > > This can lead to use-after-free or crashes in the completion callback.
> > 
> > Yes, a good catch.  Below is the fix patch.
> 
> > -- 8< --
> > From: Takashi Iwai 
> > Subject: [PATCH] ALSA: caiaq: Fix stray URB at probe error path
> > 
> > caiaq driver doesn't kill the URB properly at its error path during
> > the probe, which may lead to a use-after-free error later.  This patch
> > addresses it.
> > 
> > Reported-by: Johan Hovold 
> > Signed-off-by: Takashi Iwai 
> 
> Looks good to me:
> 
> Reviewed-by: Johan Hovold 

Thanks.  It's rather a material for for-linus with Cc to stable, so
marked it and queued.


Takashi
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