diff mbox series

USB: usblp: return error when setting unsupported protocol

Message ID 20241211154244.534745-1-jerrysteve1101@gmail.com (mailing list archive)
State Superseded
Headers show
Series USB: usblp: return error when setting unsupported protocol | expand

Commit Message

Jun Yan Dec. 11, 2024, 3:42 p.m. UTC
Fix the regression introduced by commit d8c6edfa3f4e ("USB:
usblp: don't call usb_set_interface if there's a single alt"),
which causes that unsupported protocols can also be set via
ioctl when the num_altsetting of the device is 0.

Move the check for protocol support to the earlier stage.

Fixes: d8c6edfa3f4e ("USB: usblp: don't call usb_set_interface if there's a single alt")
Signed-off-by: Jun Yan <jerrysteve1101@gmail.com>
---
 drivers/usb/class/usblp.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Greg Kroah-Hartman Dec. 11, 2024, 3:49 p.m. UTC | #1
On Wed, Dec 11, 2024 at 11:42:43PM +0800, Jun Yan wrote:
> Fix the regression introduced by commit d8c6edfa3f4e ("USB:
> usblp: don't call usb_set_interface if there's a single alt"),
> which causes that unsupported protocols can also be set via
> ioctl when the num_altsetting of the device is 0.
> 
> Move the check for protocol support to the earlier stage.
> 
> Fixes: d8c6edfa3f4e ("USB: usblp: don't call usb_set_interface if there's a single alt")
> Signed-off-by: Jun Yan <jerrysteve1101@gmail.com>
> ---
>  drivers/usb/class/usblp.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
> index 5a2e43331064..ff1a941fd2ed 100644
> --- a/drivers/usb/class/usblp.c
> +++ b/drivers/usb/class/usblp.c
> @@ -1337,11 +1337,12 @@ static int usblp_set_protocol(struct usblp *usblp, int protocol)
>  	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
>  		return -EINVAL;
>  
> +	alts = usblp->protocol[protocol].alt_setting;
> +	if (alts < 0)
> +		return -EINVAL;
> +
>  	/* Don't unnecessarily set the interface if there's a single alt. */
>  	if (usblp->intf->num_altsetting > 1) {
> -		alts = usblp->protocol[protocol].alt_setting;
> -		if (alts < 0)
> -			return -EINVAL;
>  		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
>  		if (r < 0) {
>  			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
> -- 
> 2.47.1
> 
> 

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:

- You have marked a patch with a "Fixes:" tag for a commit that is in an
  older released kernel, yet you do not have a cc: stable line in the
  signed-off-by area at all, which means that the patch will not be
  applied to any older kernel releases.  To properly fix this, please
  follow the documented rules in the
  Documentation/process/stable-kernel-rules.rst file for how to resolve
  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
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thanks,

greg k-h's patch email bot
diff mbox series

Patch

diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 5a2e43331064..ff1a941fd2ed 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -1337,11 +1337,12 @@  static int usblp_set_protocol(struct usblp *usblp, int protocol)
 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
 		return -EINVAL;
 
+	alts = usblp->protocol[protocol].alt_setting;
+	if (alts < 0)
+		return -EINVAL;
+
 	/* Don't unnecessarily set the interface if there's a single alt. */
 	if (usblp->intf->num_altsetting > 1) {
-		alts = usblp->protocol[protocol].alt_setting;
-		if (alts < 0)
-			return -EINVAL;
 		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
 		if (r < 0) {
 			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",