mmc: cd-gpio: protect against NULL context in mmc_cd_gpio_free()

commit 0e9f480bb553d39ee06ccd45639ba7a5446a7b81 upstream.

Do not oops, even if mmc_cd_gpio_free() is mistakenly called on a driver
cleanup path, even though a previous call to mmc_cd_gpio_request() failed.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
[stable@: please apply to 3.3-stable]
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/core/cd-gpio.c b/drivers/mmc/core/cd-gpio.c
index 2c14be7..f13e38d 100644 (file)
--- a/drivers/mmc/core/cd-gpio.c
+++ b/drivers/mmc/core/cd-gpio.c
@@ -73,6 +73,9 @@ void mmc_cd_gpio_free(struct mmc_host *host)
 {
        struct mmc_cd_gpio *cd = host->hotplug.handler_priv;
 
+       if (!cd)
+               return;
+
        free_irq(host->hotplug.irq, host);
        gpio_free(cd->gpio);
        kfree(cd);