From: Dan Williams <dan.j.williams@intel.com>
To: Mukesh Ojha <mojha@codeaurora.org>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>,
Kangjie Lu <kjlu@umn.edu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Aditya Pakki <pakki001@umn.edu>
Subject: Re: [PATCH v4] nvdimm: btt_devs: fix a NULL pointer dereference
Date: Tue, 26 Mar 2019 11:31:51 -0700 [thread overview]
Message-ID: <CAPcyv4jMrU4n1fOv31TOZ-8Re4-7mwG_C_d6WzxZbjnu91UVeQ@mail.gmail.com> (raw)
In-Reply-To: <5fa84f18-7253-2543-57e4-6a9e2b2da716@codeaurora.org>
On Tue, Mar 26, 2019 at 3:23 AM Mukesh Ojha <mojha@codeaurora.org> wrote:
>
>
> 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)) {
No, once the device is successfully initialized then put_device()
takes care of the rest.
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Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: Mukesh Ojha <mojha@codeaurora.org>
Cc: Aditya Pakki <pakki001@umn.edu>, Kangjie Lu <kjlu@umn.edu>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Keith Busch <keith.busch@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4] nvdimm: btt_devs: fix a NULL pointer dereference
Date: Tue, 26 Mar 2019 11:31:51 -0700 [thread overview]
Message-ID: <CAPcyv4jMrU4n1fOv31TOZ-8Re4-7mwG_C_d6WzxZbjnu91UVeQ@mail.gmail.com> (raw)
In-Reply-To: <5fa84f18-7253-2543-57e4-6a9e2b2da716@codeaurora.org>
On Tue, Mar 26, 2019 at 3:23 AM Mukesh Ojha <mojha@codeaurora.org> wrote:
>
>
> 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)) {
No, once the device is successfully initialized then put_device()
takes care of the rest.
next prev parent reply other threads:[~2019-03-26 18:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-25 21:55 [PATCH v4] nvdimm: btt_devs: fix a NULL pointer dereference Aditya Pakki
2019-03-25 21:55 ` Aditya Pakki
2019-03-26 10:23 ` Mukesh Ojha
2019-03-26 18:31 ` Dan Williams [this message]
2019-03-26 18:31 ` Dan Williams
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