[PATCH v2] usb: gadget: f_ecm: Fix ecm_opts->bound logic in bind path

[PATCH v2] usb: gadget: f_ecm: Fix ecm_opts->bound logic in bind path

[Kuen-Han Tsai]

The bound flag in ecm_opts is being set to true even if
gether_register_netdev() failed.

Move the assignment of ecm_opts->bound to after the success check to
ensure the flag only reflects the true state. The race condition on this
flag is not a concern because the caller, configfs_composite_bind(),
binds functions sequentially.

Fixes: d65e6b6e884a ("usb: gadget: f_ecm: Always set current gadget in ecm_bind()")
Cc: stable@kernel.org
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
---
 drivers/usb/gadget/function/f_ecm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
index 027226325039..9f5ed6f32a62 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -690,13 +690,14 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 
 	if (!ecm_opts->bound) {
 		status = gether_register_netdev(ecm_opts->net);
-		ecm_opts->bound = true;
 	}
 
 	mutex_unlock(&ecm_opts->lock);
 	if (status)
 		return status;
 
+	ecm_opts->bound = true;
+
 	ecm_string_defs[1].s = ecm->ethaddr;
 
 	us = usb_gstrings_attach(cdev, ecm_strings,
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v2] usb: gadget: f_ecm: Fix ecm_opts->bound logic in bind path

[Greg KH]

On Thu, Sep 04, 2025 at 02:52:00PM +0800, Kuen-Han Tsai wrote:
> The bound flag in ecm_opts is being set to true even if
> gether_register_netdev() failed.
> 
> Move the assignment of ecm_opts->bound to after the success check to
> ensure the flag only reflects the true state. The race condition on this
> flag is not a concern because the caller, configfs_composite_bind(),
> binds functions sequentially.
> 
> Fixes: d65e6b6e884a ("usb: gadget: f_ecm: Always set current gadget in ecm_bind()")
> Cc: stable@kernel.org
> Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
> ---
>  drivers/usb/gadget/function/f_ecm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
> index 027226325039..9f5ed6f32a62 100644
> --- a/drivers/usb/gadget/function/f_ecm.c
> +++ b/drivers/usb/gadget/function/f_ecm.c
> @@ -690,13 +690,14 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
>  
>  	if (!ecm_opts->bound) {
>  		status = gether_register_netdev(ecm_opts->net);
> -		ecm_opts->bound = true;
>  	}
>  
>  	mutex_unlock(&ecm_opts->lock);
>  	if (status)
>  		return status;
>  
> +	ecm_opts->bound = true;
> +
>  	ecm_string_defs[1].s = ecm->ethaddr;
>  
>  	us = usb_gstrings_attach(cdev, ecm_strings,
> -- 
> 2.51.0.338.gd7d06c2dae-goog
> 
> 


Hi,

This is the friendly semi-automated patch-bot of Greg Kroah-Hartman.
You have sent him a patch that has triggered this response.

Right now, the development tree you have sent a patch for is "closed"
due to the timing of the merge window.  Don't worry, the patch(es) you
have sent are not lost, and will be looked at after the merge window is
over (after the -rc1 kernel is released by Linus).

So thank you for your patience and your patches will be reviewed at this
later time, you do not have to do anything further, this is just a short
note to let you know the patch status and so you don't worry they didn't
make it through.

thanks,

greg k-h's patch email bot

Re: [PATCH v2] usb: gadget: f_ecm: Fix ecm_opts->bound logic in bind path

[Greg KH]

On Thu, Sep 04, 2025 at 09:33:32AM +0200, Greg KH wrote:
> On Thu, Sep 04, 2025 at 02:52:00PM +0800, Kuen-Han Tsai wrote:
> > The bound flag in ecm_opts is being set to true even if
> > gether_register_netdev() failed.
> > 
> > Move the assignment of ecm_opts->bound to after the success check to
> > ensure the flag only reflects the true state. The race condition on this
> > flag is not a concern because the caller, configfs_composite_bind(),
> > binds functions sequentially.
> > 
> > Fixes: d65e6b6e884a ("usb: gadget: f_ecm: Always set current gadget in ecm_bind()")
> > Cc: stable@kernel.org
> > Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
> > ---
> >  drivers/usb/gadget/function/f_ecm.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
> > index 027226325039..9f5ed6f32a62 100644
> > --- a/drivers/usb/gadget/function/f_ecm.c
> > +++ b/drivers/usb/gadget/function/f_ecm.c
> > @@ -690,13 +690,14 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
> >  
> >  	if (!ecm_opts->bound) {
> >  		status = gether_register_netdev(ecm_opts->net);
> > -		ecm_opts->bound = true;
> >  	}
> >  
> >  	mutex_unlock(&ecm_opts->lock);
> >  	if (status)
> >  		return status;
> >  
> > +	ecm_opts->bound = true;
> > +
> >  	ecm_string_defs[1].s = ecm->ethaddr;
> >  
> >  	us = usb_gstrings_attach(cdev, ecm_strings,
> > -- 
> > 2.51.0.338.gd7d06c2dae-goog
> > 
> > 
> 
> 
> Hi,
> 
> This is the friendly semi-automated patch-bot of Greg Kroah-Hartman.
> You have sent him a patch that has triggered this response.
> 
> Right now, the development tree you have sent a patch for is "closed"
> due to the timing of the merge window.  Don't worry, the patch(es) you
> have sent are not lost, and will be looked at after the merge window is
> over (after the -rc1 kernel is released by Linus).
> 
> So thank you for your patience and your patches will be reviewed at this
> later time, you do not have to do anything further, this is just a short
> note to let you know the patch status and so you don't worry they didn't
> make it through.
> 
> thanks,
> 
> greg k-h's patch email bot

Oops, nope, wrong bot, forgot to turn this one off...

Re: [PATCH v2] usb: gadget: f_ecm: Fix ecm_opts->bound logic in bind path

[Greg KH]

On Thu, Sep 04, 2025 at 02:52:00PM +0800, Kuen-Han Tsai wrote:
> The bound flag in ecm_opts is being set to true even if
> gether_register_netdev() failed.
> 
> Move the assignment of ecm_opts->bound to after the success check to
> ensure the flag only reflects the true state. The race condition on this
> flag is not a concern because the caller, configfs_composite_bind(),
> binds functions sequentially.
> 
> Fixes: d65e6b6e884a ("usb: gadget: f_ecm: Always set current gadget in ecm_bind()")
> Cc: stable@kernel.org
> Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
> ---
>  drivers/usb/gadget/function/f_ecm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
> index 027226325039..9f5ed6f32a62 100644
> --- a/drivers/usb/gadget/function/f_ecm.c
> +++ b/drivers/usb/gadget/function/f_ecm.c
> @@ -690,13 +690,14 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
>  
>  	if (!ecm_opts->bound) {
>  		status = gether_register_netdev(ecm_opts->net);
> -		ecm_opts->bound = true;
>  	}
>  
>  	mutex_unlock(&ecm_opts->lock);
>  	if (status)
>  		return status;
>  
> +	ecm_opts->bound = true;
> +
>  	ecm_string_defs[1].s = ecm->ethaddr;
>  
>  	us = usb_gstrings_attach(cdev, ecm_strings,
> -- 
> 2.51.0.338.gd7d06c2dae-goog
> 
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/process/submitting-patches.rst for what
  needs to be done here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot