Messages in this thread | | | Subject | Re: [PATCH v4] nvdimm: btt_devs: fix a NULL pointer dereference | From | Mukesh Ojha <> | Date | Tue, 26 Mar 2019 15:53:07 +0530 |
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On 3/26/2019 3:25 AM, Aditya Pakki wrote: > In case kmemdup fails, the fix releases resources and returns to > avoid the NULL pointer dereference. > > Signed-off-by: Aditya Pakki <pakki001@umn.edu> > > --- > v3: Move kfree(nd_btt) to goto block. > v2: Replace incorrect kfree with ida_simple_remove, suggested by > Johannes Thumshirn > v1: Free nd_btt->id in case of failure and avoid double free, suggested > by Dan Williams > --- > drivers/nvdimm/btt_devs.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c > index b72a303176c7..9486acc08402 100644 > --- a/drivers/nvdimm/btt_devs.c > +++ b/drivers/nvdimm/btt_devs.c > @@ -198,14 +198,15 @@ static struct device *__nd_btt_create(struct nd_region *nd_region, > return NULL; > > nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL); > - if (nd_btt->id < 0) { > - kfree(nd_btt); > - return NULL; > - } > + if (nd_btt->id < 0) > + goto out_nd_btt; > > nd_btt->lbasize = lbasize; > - if (uuid) > + if (uuid) { > uuid = kmemdup(uuid, 16, GFP_KERNEL); > + if (!uuid) > + goto out_put_id; > + } > nd_btt->uuid = uuid; > dev = &nd_btt->dev; > dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id); > @@ -220,6 +221,13 @@ static struct device *__nd_btt_create(struct nd_region *nd_region, > return NULL; > } > return dev; > + > +out_put_id: > + ida_simple_remove(&nd_region->btt_ida, nd_btt->id); > + > +out_nd_btt: > + kfree(nd_btt); > + return NULL; > } > > struct device *nd_btt_create(struct nd_region *nd_region)
you have to take care of this below if block(true) as well as you are touching the function. if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
Thanks, Mukesh
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