From: Dan Carpenter <dan.carpenter@oracle.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: [bug report] libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure
Date: Wed, 5 Feb 2020 21:10:40 +0300 [thread overview]
Message-ID: <20200205181040.GC24804@kadam> (raw)
In-Reply-To: <CAPcyv4j12vgjgEgY3xAr9bpV8dd+3E7Q5Q3OFo2AXmwnN45PBA@mail.gmail.com>
On Wed, Feb 05, 2020 at 09:47:01AM -0800, Dan Williams wrote:
> On Wed, Feb 5, 2020 at 4:38 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > Hello Dan Williams,
> >
> > The patch 4d88a97aa9e8: "libnvdimm, nvdimm: dimm driver and base
> > libnvdimm device-driver infrastructure" from May 31, 2015, leads to
> > the following static checker warning:
> >
> > drivers/nvdimm/bus.c:511 nd_async_device_register()
> > error: dereferencing freed memory 'dev'
> >
> > drivers/nvdimm/bus.c
> > 502 static void nd_async_device_register(void *d, async_cookie_t cookie)
> > 503 {
> > 504 struct device *dev = d;
> > 505
> > 506 if (device_add(dev) != 0) {
> > 507 dev_err(dev, "%s: failed\n", __func__);
> > 508 put_device(dev);
> > ^^^^^^^^^^^^^^^
> > 509 }
> > 510 put_device(dev);
> > ^^^^^^^^^^^^^^
> > 511 if (dev->parent)
> > 512 put_device(dev->parent);
> > 513 }
> >
> > We call get_device() from __nd_device_register(), I guess. It seems
> > buggy to call put device twice on error.
>
> The registration path does:
>
> get_device(dev);
>
> async_schedule_dev_domain(nd_async_device_register, dev,
> &nd_async_domain);
>
> ...and device_add() does its own get_device().
device_add() does its own put_device() at the end so it's a net zero.
regards,
dan carpenter
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next prev parent reply other threads:[~2020-02-05 18:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 12:38 [bug report] libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure Dan Carpenter
2020-02-05 17:47 ` Dan Williams
2020-02-05 18:10 ` Dan Carpenter [this message]
2020-02-05 18:23 ` Dan Williams
2020-02-05 19:08 ` Dan Carpenter
2020-02-05 19:16 ` Dan Williams
2020-02-05 19:28 ` Dan Carpenter
2020-02-05 20:04 ` Dan Williams
2020-02-05 20:18 ` Dan Carpenter
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