From: Lars-Peter Clausen Date: Tue, 18 Oct 2016 14:53:59 +0000 (+0200) Subject: gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation X-Git-Tag: v4.9-rc3~39^2~10 X-Git-Url: http://git.cascardo.eti.br/?a=commitdiff_plain;h=1f1cc4566bd9dd8d3cf19965a4b6392143618536;p=cascardo%2Flinux.git gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation The current line offset validation is off by one. Depending on the data stored behind the descs array this can either cause undefined behavior or disclose arbitrary, potentially sensitive, memory to the issuing userspace application. Make sure that offset is within the bounds of the desc array. Cc: stable@vger.kernel.org Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information") Signed-off-by: Lars-Peter Clausen Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index f0fc3a0d37c8..dac975397253 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -839,7 +839,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; - if (lineinfo.line_offset > gdev->ngpio) + if (lineinfo.line_offset >= gdev->ngpio) return -EINVAL; desc = &gdev->descs[lineinfo.line_offset];