linux-kernel - Re: [PATCH] scsi: core: Correct wrong kfree() usage for `kobj->name`

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Message-ID: <2026011658-fervor-possibly-4af2@gregkh>
Date: Fri, 16 Jan 2026 11:50:15 +0100
From: Greg KH <gregkh@...uxfoundation.org>
To: Tzung-Bi Shih <tzungbi@...nel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@...senpartnership.com>,
	"Martin K. Petersen" <martin.petersen@...cle.com>,
	linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Subject: Re: [PATCH] scsi: core: Correct wrong kfree() usage for `kobj->name`

On Fri, Jan 16, 2026 at 09:37:07AM +0000, Tzung-Bi Shih wrote:
> On Fri, Jan 16, 2026 at 10:00:11AM +0100, Greg KH wrote:
> > On Fri, Jan 16, 2026 at 08:13:59AM +0000, Tzung-Bi Shih wrote:
> > > `kobj->name` should be freed by kfree_const()[1][2].  Correct it.
> > > 
> > > [1] https://elixir.bootlin.com/linux/v6.18/source/lib/kasprintf.c#L41
> > > [2] https://elixir.bootlin.com/linux/v6.18/source/lib/kobject.c#L695
> > > 
> > > Cc: stable@...r.kernel.org
> > > Fixes: b49493f99690 ("Fix a memory leak in scsi_host_dev_release()")
> > > Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
> > > ---
> > >  drivers/scsi/hosts.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
> > > index e047747d4ecf..50ec782cf9f4 100644
> > > --- a/drivers/scsi/hosts.c
> > > +++ b/drivers/scsi/hosts.c
> > > @@ -373,7 +373,7 @@ static void scsi_host_dev_release(struct device *dev)
> > >  		 * name as well as the proc dir structure are leaked.
> > >  		 */
> > >  		scsi_proc_hostdir_rm(shost->hostt);
> > > -		kfree(dev_name(&shost->shost_dev));
> > > +		kfree_const(dev_name(&shost->shost_dev));
> > 
> > Shouldn't the struct device name be freed by the driver core for this
> > device when it goes out of scope?  Why is it being manually freed here
> > at all?
> 
> Ah, correct.  I think the following patch is what it really needs:
> 
> diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
> index 1b3fbd328277..e3362f445f93 100644
> --- a/drivers/scsi/hosts.c
> +++ b/drivers/scsi/hosts.c
> @@ -373,7 +373,6 @@ static void scsi_host_dev_release(struct device *dev)
>  		 * name as well as the proc dir structure are leaked.
>  		 */
>  		scsi_proc_hostdir_rm(shost->hostt);
> -		kfree(dev_name(&shost->shost_dev));
>  	}
> 
>  	kfree(shost->shost_data);
> @@ -548,11 +547,7 @@ struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int priv
>  		goto fail;
>  	return shost;
>   fail:
> -	/*
> -	 * Host state is still SHOST_CREATED and that is enough to release
> -	 * ->shost_gendev. scsi_host_dev_release() will free
> -	 * dev_name(&shost->shost_dev).
> -	 */
> +	put_device(&shost->shost_dev);
>  	put_device(&shost->shost_gendev);
> 
>  	return NULL;

Can you test this to verify that the leak you were seeing is actually
now handled?

thanks,

greg k-h