linux-kernel - [PATCH] gpiolib: fix freeing of descriptors on error

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Date:   Thu, 13 Sep 2018 12:35:41 -0400
From:   Jim Paris <jim@...n.com>
To:     linux-kernel@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        linux-gpio@...r.kernel.org, Jim Paris <jim@...n.com>,
        stable@...r.kernel.org
Subject: [PATCH] gpiolib: fix freeing of descriptors on error

When the main loop in linehandle_create() encounters an error, it
fails to free one of the previously-requested GPIO descriptors.
This renders the unfreed GPIO unusable until reboot, and leaves
its label pointing to free'd kernel memory.

Cc: stable@...r.kernel.org
Fixes: ab3dbcf78f60 ("gpioib: do not free unrequested descriptors")
Signed-off-by: Jim Paris <jim@...n.com>
---
 drivers/gpio/gpiolib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e8f8a1999393..a57300c1d649 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -571,7 +571,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 		if (ret)
 			goto out_free_descs;
 		lh->descs[i] = desc;
-		count = i;
+		count = i + 1;
 
 		if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
 			set_bit(FLAG_ACTIVE_LOW, &desc->flags);
-- 
2.18.0