From: Ian Abbott <abbotti@mev.co.uk>
To: Dan Carpenter <dan.carpenter@oracle.com>,
Navid Emamdoost <navid.emamdoost@gmail.com>
Cc: devel@driverdev.osuosl.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
kjlu@umn.edu, linux-kernel@vger.kernel.org, emamd001@umn.edu,
smccaman@umn.edu
Subject: Re: [PATCH] staging: comedi: drivers: prevent memory leak
Date: Tue, 17 Sep 2019 11:13:15 +0100 [thread overview]
Message-ID: <86a2ceb0-cc59-2b57-e2b0-f620a42e9ac1@mev.co.uk> (raw)
In-Reply-To: <20190917063004.GG18977@kadam>
On 17/09/2019 07:33, Dan Carpenter wrote:
> On Mon, Sep 16, 2019 at 09:41:43PM -0500, Navid Emamdoost wrote:
>> In das1800_attach, the buffer allocated via kmalloc_array needs to be
>> released if an error happens.
>>
>> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
>
> Commedit calls ->detach() if the ->attach() fails so this patch would
> lead to a double free. See comedi_device_attach():
>
> drivers/staging/comedi/drivers.c
> 983 }
> 984 if (!driv->attach) {
> 985 /* driver does not support manual configuration */
> 986 dev_warn(dev->class_dev,
> 987 "driver '%s' does not support attach using comedi_config\n",
> 988 driv->driver_name);
> 989 module_put(driv->module);
> 990 ret = -EIO;
> 991 goto out;
> 992 }
> 993 dev->driver = driv;
> 994 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
> 995 : dev->driver->driver_name;
> 996 ret = driv->attach(dev, it);
> ^^^^^^^^^^^^^^^^^^^^^
> 997 if (ret >= 0)
> 998 ret = comedi_device_postconfig(dev);
> 999 if (ret < 0) {
> 1000 comedi_device_detach(dev);
> ^^^^^^^^^^^^^^^^^^^^^^^^^
>
> 1001 module_put(driv->module);
> 1002 }
> 1003 /* On success, the driver module count has been incremented. */
Yes, everything should be freed properly by comedi_device_detach().
From comedi_device_detach(), some of the stuff is freed by
dev->driver->detach(), and the remainder is freed by
comedi_device_detach_cleanup().
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prev parent reply other threads:[~2019-09-17 10:13 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 2:41 Navid Emamdoost
2019-09-17 6:33 ` Dan Carpenter
2019-09-17 10:13 ` Ian Abbott [this message]
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