From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kim, Milo" Subject: Re: [PATCH v2] leds: lp55xx: avoid dereferencing a stale platform_data pointer Date: Thu, 6 Aug 2015 14:44:17 +0900 Message-ID: <55C2F431.3030107@ti.com> References: <1438679930-26080-1-git-send-email-toshik@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:50657 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754317AbbHFFoV (ORCPT ); Thu, 6 Aug 2015 01:44:21 -0400 In-Reply-To: <1438679930-26080-1-git-send-email-toshik@chromium.org> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Toshi Kikuchi , linux-leds@vger.kernel.org Hi Toshi, On 8/4/2015 6:18 PM, Toshi Kikuchi wrote: > lp55xx_of_populate_pdata() allocates platform_data dynamically if DT > is used. The memory area is allocated with devm_kzalloc() so it is > automatically freed if the driver is unloaded. The driver should clear > the pointer to platform_data before it is unloaded, otherwise it will > use the stale pointer accidentally if the driver is reloaded. > > Change-Id: Ia097ed83b92cec5a52534a71dcb5322869c2a7b1 > Signed-off-by: Toshi Kikuchi Acked-by: Milo Kim > --- > drivers/leds/leds-lp5521.c | 1 + > drivers/leds/leds-lp5523.c | 1 + > drivers/leds/leds-lp5562.c | 1 + > drivers/leds/leds-lp55xx-common.c | 7 +++++++ > drivers/leds/leds-lp55xx-common.h | 2 ++ > drivers/leds/leds-lp8501.c | 1 + > 6 files changed, 13 insertions(+) > > diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c > index 8ca197a..faba1f9 100644 > --- a/drivers/leds/leds-lp5521.c > +++ b/drivers/leds/leds-lp5521.c > @@ -581,6 +581,7 @@ static int lp5521_remove(struct i2c_client *client) > lp55xx_unregister_sysfs(chip); > lp55xx_unregister_leds(led, chip); > lp55xx_deinit_device(chip); > + lp55xx_of_reset_pdata(&client->dev, client->dev.of_node); > > return 0; > } > diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c > index 584dbbc..4fc2850 100644 > --- a/drivers/leds/leds-lp5523.c > +++ b/drivers/leds/leds-lp5523.c > @@ -947,6 +947,7 @@ static int lp5523_remove(struct i2c_client *client) > lp55xx_unregister_sysfs(chip); > lp55xx_unregister_leds(led, chip); > lp55xx_deinit_device(chip); > + lp55xx_of_reset_pdata(&client->dev, client->dev.of_node); > > return 0; > } > diff --git a/drivers/leds/leds-lp5562.c b/drivers/leds/leds-lp5562.c > index ca85724..9d8c250 100644 > --- a/drivers/leds/leds-lp5562.c > +++ b/drivers/leds/leds-lp5562.c > @@ -581,6 +581,7 @@ static int lp5562_remove(struct i2c_client *client) > lp55xx_unregister_sysfs(chip); > lp55xx_unregister_leds(led, chip); > lp55xx_deinit_device(chip); > + lp55xx_of_reset_pdata(&client->dev, client->dev.of_node); > > return 0; > } > diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c > index 96d51e9..ec29163 100644 > --- a/drivers/leds/leds-lp55xx-common.c > +++ b/drivers/leds/leds-lp55xx-common.c > @@ -594,6 +594,13 @@ int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np) > } > EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata); > > +void lp55xx_of_reset_pdata(struct device *dev, struct device_node *np) > +{ > + if (np) > + dev->platform_data = NULL; > +} > +EXPORT_SYMBOL_GPL(lp55xx_of_reset_pdata); > + > MODULE_AUTHOR("Milo Kim "); > MODULE_DESCRIPTION("LP55xx Common Driver"); > MODULE_LICENSE("GPL"); > diff --git a/drivers/leds/leds-lp55xx-common.h b/drivers/leds/leds-lp55xx-common.h > index cceab48..2a6a8fc 100644 > --- a/drivers/leds/leds-lp55xx-common.h > +++ b/drivers/leds/leds-lp55xx-common.h > @@ -204,5 +204,7 @@ extern void lp55xx_unregister_sysfs(struct lp55xx_chip *chip); > /* common device tree population function */ > extern int lp55xx_of_populate_pdata(struct device *dev, > struct device_node *np); > +extern void lp55xx_of_reset_pdata(struct device *dev, > + struct device_node *np); > > #endif /* _LEDS_LP55XX_COMMON_H */ > diff --git a/drivers/leds/leds-lp8501.c b/drivers/leds/leds-lp8501.c > index d3098e3..d75a6f3 100644 > --- a/drivers/leds/leds-lp8501.c > +++ b/drivers/leds/leds-lp8501.c > @@ -375,6 +375,7 @@ static int lp8501_remove(struct i2c_client *client) > lp55xx_unregister_sysfs(chip); > lp55xx_unregister_leds(led, chip); > lp55xx_deinit_device(chip); > + lp55xx_of_reset_pdata(&client->dev, client->dev.of_node); > > return 0; > } >