Re: [PATCH] [SCSI] iscsi_boot_sysfs: Fix a memory leak in iscsi_boot_destroy_kset()

[Mike Christie]

On 12/10/13 8:11 AM, Konrad Rzeszutek Wilk wrote:
> Ethan Zhao <ethan.kernel@xxxxxxxxx> wrote:
> > Konrad,
> >
> > boot_kset was allocated when module loaded by
> > ibft_init()
> >   iscsi_boot_create_kset()
> >      kzalloc()
> >
> > but wasn't freed when module unloaded by
> > ibft_exit()
> >    ibft_cleanup()
> >      iscsi_boot_destroy_kset()
> >
> > Thanks,
> > Ethan
> >
> > On Tue, Dec 10, 2013 at 5:30 AM, Konrad Rzeszutek Wilk
> > <konrad.wilk@xxxxxxxxxx> wrote:
> > > On Mon, Dec 09, 2013 at 05:37:11PM +0800, Ethan Zhao wrote:
> > > > From: "Ethan Zhao" <ethan.kernel@xxxxxxxxx>
> > > >
> > > > Load and unload iscsi_ibft module will cause kernel memory leak, fix
> > it
> > > > in scsi/iscsi_boot_sysfs.c iscsi_boot_destroy_kset().
> > >
> > > Is there a stack trace?
> > > > Signed-off-by: Ethan Zhao <ethan.kernel@xxxxxxxxx>
> > > > ---
> > > >   drivers/scsi/iscsi_boot_sysfs.c | 1 +
> > > >   1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/scsi/iscsi_boot_sysfs.c
> > b/drivers/scsi/iscsi_boot_sysfs.c
> > > > index 14c1c8f..680bf6f 100644
> > > > --- a/drivers/scsi/iscsi_boot_sysfs.c
> > > > +++ b/drivers/scsi/iscsi_boot_sysfs.c
> > > > @@ -490,5 +490,6 @@ void iscsi_boot_destroy_kset(struct
> > iscsi_boot_kset *boot_kset)
> > > >                iscsi_boot_remove_kobj(boot_kobj);
> > > >
> > > >        kset_unregister(boot_kset->kset);
> > > > +     kfree(boot_kset);
> > > >   }
> > > >   EXPORT_SYMBOL_GPL(iscsi_boot_destroy_kset);
> > > > --
> > > > 1.8.3.4 (Apple Git-47)
>
> Right. In the past we did not do that b/c certain drivers (like broadcom) would allocate on the kset their name and try to free (the driver would after freeing the ibft). So you would end up with this patch a double free ( and it might be fixed by now but I can't recall).

Do you mean the name string that is passed into kset_create_and_add? If 
so that should not happen now. There does not seem to be any user 
freeing that string.

There used to be bug where at the initiator/target/ethernet level there 
was a double free because iscsi_boot_sysfs and be2iscsi were both 
freeing the struct associated with the initiator/target/ethernet. That 
is fixed in f457a46f179df41b0f6d80dee33b6e629945f276.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/