Re: [PATCH v2 3/7] dmaengine: idxd: fix memory leak in error handling path of idxd_setup_groups

[Shuai Xue]

在 2025/2/19 04:20, Fenghua Yu 写道:
> Hi, Shuai,
>
> On 2/14/25 21:44, Shuai Xue wrote:
> > Memory allocated for groups is not freed if an error occurs during
> > idxd_setup_groups(). To fix it, free the allocated memory in the reverse
> > order of allocation before exiting the function in case of an error.
> >
> > Fixes: defe49f96012 ("dmaengine: idxd: fix group conf_dev lifetime")
> > Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> > Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> > ---
> >   drivers/dma/idxd/init.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> > index 4e47075c5bef..a2da68e6144d 100644
> > --- a/drivers/dma/idxd/init.c
> > +++ b/drivers/dma/idxd/init.c
> > @@ -328,6 +328,7 @@ static int idxd_setup_groups(struct idxd_device *idxd)
> >           rc = dev_set_name(conf_dev, "group%d.%d", idxd->id, group->id);
> >           if (rc < 0) {
> >               put_device(conf_dev);
> > +            kfree(group);
> >               goto err;
> >           }
> > @@ -352,7 +353,10 @@ static int idxd_setup_groups(struct idxd_device *idxd)
> >       while (--i >= 0) {
> >           group = idxd->groups[i];
> >           put_device(group_confdev(group));
> > +        kfree(group);
> >       }
> > +    kfree(idxd->groups);
> > +
>
> What happens to the memory areas previously allocated for wqs and engines after idxd_setup_groups() fails? They need to be freed as well, but currently they are not.
>
> Maybe a separate patch cleans up the previously allocated mem areas for wqs/engines/groups if there is any failure after the allocations?

Agreed, will add a new patch to fix it.

Thanks
Shuai