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

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Dec 11, 2013 at 12:18:19PM -0500, Konrad Rzeszutek Wilk wrote:
> On Tue, Dec 10, 2013 at 12:46:36PM -0600, Mike Christie wrote:
> > On 12/10/13 8:11 AM, Konrad Rzeszutek Wilk wrote:
> > >Ethan Zhao <ethan.kernel@gmail.com> 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@oracle.com> wrote:
> > >>>On Mon, Dec 09, 2013 at 05:37:11PM +0800, Ethan Zhao wrote:
> > >>>>From: "Ethan Zhao" <ethan.kernel@gmail.com>
> > >>>>
> > >>>>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@gmail.com>
> > >>>>---
> > >>>>  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?
> 
> Yes.
> > 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.
> 
> That is the one!

With that in mind, do you want to carry this patch to Linus (or James) or should I do it?
> > 
> >