[PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[Deepanshu Kartikey]

u_audio_get_playback_srate() unconditionally locks and reads
uac->p_prm.lock/srate, but g_audio_setup() only initializes
p_prm.lock when p_chmask is set. On a UAC2 instance configured
without a playback direction, this results in acquiring a
never spin_lock_init()'d lock when a GET_CUR sample rate
request targets playback, triggering a lockdep "trying to
register non-static key" warning.

Reject the request with -EOPNOTSUPP when p_chmask is not set,
before touching prm->lock.

Fixes: eb3a1ce6f5ed ("usb: gadget: u_audio: Add capture/playback srate getter")
Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 drivers/usb/gadget/function/u_audio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index e53f2927b539..ff811ea1e25a 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
 	struct uac_rtd_params *prm;
 	unsigned long flags;
 
+	if (!audio_dev->params.p_chmask)
+		return -EOPNOTSUPP;
+
 	prm = &uac->p_prm;
 	spin_lock_irqsave(&prm->lock, flags);
 	*val = prm->srate;
-- 
2.43.0

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[Deepanshu Kartikey]

On Fri, Aug 21, 2026 at 5:19 PM Deepanshu Kartikey
<kartikey406@gmail.com> wrote:
>
> u_audio_get_playback_srate() unconditionally locks and reads
> uac->p_prm.lock/srate, but g_audio_setup() only initializes
> p_prm.lock when p_chmask is set. On a UAC2 instance configured
> without a playback direction, this results in acquiring a
> never spin_lock_init()'d lock when a GET_CUR sample rate
> request targets playback, triggering a lockdep "trying to
> register non-static key" warning.
>
> Reject the request with -EOPNOTSUPP when p_chmask is not set,
> before touching prm->lock.
>
> Fixes: eb3a1ce6f5ed ("usb: gadget: u_audio: Add capture/playback srate getter")
> Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> ---
>  drivers/usb/gadget/function/u_audio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> index e53f2927b539..ff811ea1e25a 100644
> --- a/drivers/usb/gadget/function/u_audio.c
> +++ b/drivers/usb/gadget/function/u_audio.c
> @@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
>         struct uac_rtd_params *prm;
>         unsigned long flags;
>
> +       if (!audio_dev->params.p_chmask)
> +               return -EOPNOTSUPP;
> +
>         prm = &uac->p_prm;
>         spin_lock_irqsave(&prm->lock, flags);
>         *val = prm->srate;
> --
> 2.43.0
>

Gentle Reminder. Please let me know the status of this patch

Thanks

Deepanshu

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[Deepanshu Kartikey]

On Fri, Aug 21, 2026 at 5:19 PM Deepanshu Kartikey
<kartikey406@gmail.com> wrote:
>
> u_audio_get_playback_srate() unconditionally locks and reads
> uac->p_prm.lock/srate, but g_audio_setup() only initializes
> p_prm.lock when p_chmask is set. On a UAC2 instance configured
> without a playback direction, this results in acquiring a
> never spin_lock_init()'d lock when a GET_CUR sample rate
> request targets playback, triggering a lockdep "trying to
> register non-static key" warning.
>
> Reject the request with -EOPNOTSUPP when p_chmask is not set,
> before touching prm->lock.
>
> Fixes: eb3a1ce6f5ed ("usb: gadget: u_audio: Add capture/playback srate getter")
> Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> ---
>  drivers/usb/gadget/function/u_audio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> index e53f2927b539..ff811ea1e25a 100644
> --- a/drivers/usb/gadget/function/u_audio.c
> +++ b/drivers/usb/gadget/function/u_audio.c
> @@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
>         struct uac_rtd_params *prm;
>         unsigned long flags;
>
> +       if (!audio_dev->params.p_chmask)
> +               return -EOPNOTSUPP;
> +
>         prm = &uac->p_prm;
>         spin_lock_irqsave(&prm->lock, flags);
>         *val = prm->srate;
> --
> 2.43.0
>

Gentle Reminder. Please let me know the status of this patch.

Thanks

Deepanshu

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[Greg KH]

On Wed, Sep 23, 2026 at 09:01:22AM +0530, Deepanshu Kartikey wrote:
> On Fri, Aug 21, 2026 at 5:19 PM Deepanshu Kartikey
> <kartikey406@gmail.com> wrote:
> >
> > u_audio_get_playback_srate() unconditionally locks and reads
> > uac->p_prm.lock/srate, but g_audio_setup() only initializes
> > p_prm.lock when p_chmask is set. On a UAC2 instance configured
> > without a playback direction, this results in acquiring a
> > never spin_lock_init()'d lock when a GET_CUR sample rate
> > request targets playback, triggering a lockdep "trying to
> > register non-static key" warning.
> >
> > Reject the request with -EOPNOTSUPP when p_chmask is not set,
> > before touching prm->lock.
> >
> > Fixes: eb3a1ce6f5ed ("usb: gadget: u_audio: Add capture/playback srate getter")
> > Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> > Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> > Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> > ---
> >  drivers/usb/gadget/function/u_audio.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> > index e53f2927b539..ff811ea1e25a 100644
> > --- a/drivers/usb/gadget/function/u_audio.c
> > +++ b/drivers/usb/gadget/function/u_audio.c
> > @@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
> >         struct uac_rtd_params *prm;
> >         unsigned long flags;
> >
> > +       if (!audio_dev->params.p_chmask)
> > +               return -EOPNOTSUPP;
> > +
> >         prm = &uac->p_prm;
> >         spin_lock_irqsave(&prm->lock, flags);
> >         *val = prm->srate;
> > --
> > 2.43.0
> >
> 
> Gentle Reminder. Please let me know the status of this patch.

If you wish to see patches reviewed quicker, please help out and review
other submissions which will cause your patch to move to the top.

thanks,

greg k-h

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[Greg KH]

On Fri, Aug 21, 2026 at 05:18:54PM +0530, Deepanshu Kartikey wrote:
> u_audio_get_playback_srate() unconditionally locks and reads
> uac->p_prm.lock/srate, but g_audio_setup() only initializes
> p_prm.lock when p_chmask is set. On a UAC2 instance configured
> without a playback direction, this results in acquiring a
> never spin_lock_init()'d lock when a GET_CUR sample rate
> request targets playback, triggering a lockdep "trying to
> register non-static key" warning.
> 
> Reject the request with -EOPNOTSUPP when p_chmask is not set,
> before touching prm->lock.
> 
> Fixes: eb3a1ce6f5ed ("usb: gadget: u_audio: Add capture/playback srate getter")
> Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> ---

How was this tested?

Did you forget a Assisted-by: tag?

thanks,

greg k-h

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[syzbot]

> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

This crash does not have a reproducer. I cannot test it.

>
> u_audio_get_playback_srate() unconditionally locks and reads
> uac->p_prm.lock/srate, but g_audio_setup() only initializes
> p_prm.lock when p_chmask is set. On a UAC2 instance configured
> without a playback direction, this results in acquiring a
> never spin_lock_init()'d lock when a GET_CUR sample rate
> request targets playback, triggering a lockdep "trying to
> register non-static key" warning.
>
> Reject the request with -EOPNOTSUPP when p_chmask is not set,
> before touching prm->lock.
>
> Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> ---
>  drivers/usb/gadget/function/u_audio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> index e53f2927b539..ff811ea1e25a 100644
> --- a/drivers/usb/gadget/function/u_audio.c
> +++ b/drivers/usb/gadget/function/u_audio.c
> @@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
>  	struct uac_rtd_params *prm;
>  	unsigned long flags;
>  
> +	if (!audio_dev->params.p_chmask)
> +		return -EOPNOTSUPP;
> +
>  	prm = &uac->p_prm;
>  	spin_lock_irqsave(&prm->lock, flags);
>  	*val = prm->srate;
> -- 
> 2.43.0
>

Re: [PATCH] usb: gadget: u_audio: reject srate request for unconfigured direction

[syzbot]

> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

This crash does not have a reproducer. I cannot test it.

>
>
> u_audio_get_playback_srate() unconditionally locks and reads
> uac->p_prm.lock/srate, but g_audio_setup() only initializes
> p_prm.lock when p_chmask is set. On a UAC2 instance configured
> without a playback direction, this results in acquiring a
> never spin_lock_init()'d lock when a GET_CUR sample rate
> request targets playback, triggering a lockdep "trying to
> register non-static key" warning.
>
> Reject the request with -EOPNOTSUPP when p_chmask is not set,
> before touching prm->lock.
>
> Reported-by: syzbot+e1d0e66badecc32d45eb@syzkaller.appspotmail.com
> Closes: http://syzkaller.appspot.com/bug?extid=e1d0e66badecc32d45eb
> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> ---
>  drivers/usb/gadget/function/u_audio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> index e53f2927b539..ff811ea1e25a 100644
> --- a/drivers/usb/gadget/function/u_audio.c
> +++ b/drivers/usb/gadget/function/u_audio.c
> @@ -575,6 +575,9 @@ int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
>  	struct uac_rtd_params *prm;
>  	unsigned long flags;
>  
> +	if (!audio_dev->params.p_chmask)
> +		return -EOPNOTSUPP;
> +
>  	prm = &uac->p_prm;
>  	spin_lock_irqsave(&prm->lock, flags);
>  	*val = prm->srate;
> -- 
> 2.43.0
>