Messages in this thread | | | Subject | Re: [PATCH v2] nvdimm: btt_devs: fix a NULL pointer dereference | From | Johannes Thumshirn <> | Date | Mon, 25 Mar 2019 09:56:36 +0100 |
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On 23/03/2019 22:41, 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> > > --- > v1: Free nd_btt->id in case of failure and avoid double free, suggested > by Dan Williams > --- > drivers/nvdimm/btt_devs.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c > index b72a303176c7..119a4ead2e46 100644 > --- a/drivers/nvdimm/btt_devs.c > +++ b/drivers/nvdimm/btt_devs.c > @@ -204,8 +204,14 @@ static struct device *__nd_btt_create(struct nd_region *nd_region, > } > > nd_btt->lbasize = lbasize; > - if (uuid) > + if (uuid) { > uuid = kmemdup(uuid, 16, GFP_KERNEL); > + if (!uuid) { > + kfree(nd_btt->id); > + kfree(nd_btt); > + return NULL; > + } > + }
nd_btt->id is an ida and thus must be freed using: ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
that being I'd prefer a 'out_put_id' label at the end of the function and to the cleanups there.
Something like this:
if (uuid) { uuid = kmemdup(uuid, 16, GFP_KERNEL); if (!uuid) goto out_put_id;
[...]
return dev;
out_put_id: ida_simple_remove(&nd_region->btt_ida, nd_btt->id); kfree(nd_btt); return NULL; }
-- Johannes Thumshirn SUSE Labs Filesystems jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
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