Re: [PATCH] gfs2: Fix error path kobject memory leak

From: Tobin C. Harding
Date: Mon May 13 2019 - 06:50:32 EST


On Mon, May 13, 2019 at 09:14:05AM +0200, Greg Kroah-Hartman wrote:
> On Mon, May 13, 2019 at 01:32:13PM +1000, Tobin C. Harding wrote:
> > If a call to kobject_init_and_add() fails we must call kobject_put()
> > otherwise we leak memory.
> >
> > Function always calls kobject_init_and_add() which always calls
> > kobject_init().
> >
> > It is safe to leave object destruction up to the kobject release
> > function and never free it manually.
> >
> > Remove call to kfree() and always call kobject_put() in the error path.
> >
> > Signed-off-by: Tobin C. Harding <tobin@xxxxxxxxxx>
> > ---
> >
> > Is it ok to send patches during the merge window?
> >
> > Applies on top of Linus' mainline tag: v5.1
> >
> > Happy to rebase if there are conflicts.
> >
> > thanks,
> > Tobin.
> >
> > fs/gfs2/sys.c | 7 +------
> > 1 file changed, 1 insertion(+), 6 deletions(-)
> >
> > diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
> > index 1787d295834e..98586b139386 100644
> > --- a/fs/gfs2/sys.c
> > +++ b/fs/gfs2/sys.c
> > @@ -661,8 +661,6 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
> > if (error)
> > goto fail_reg;
> >
> > - sysfs_frees_sdp = 1; /* Freeing sdp is now done by sysfs calling
> > - function gfs2_sbd_release. */
>
> You should also delete this variable at the top of the function, as it
> is now only set once there and never used.

Thanks, I should have gotten a compiler warning for that. I was feeling
so confident with my builds this morning ... pays not to get too cocky
I suppose.

> With that:
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Thanks, will re-spin.

Tobin.