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: v4.8.7~130 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78ae767553e435d5c3d71521b39d52e3a2e226b1;p=thirdparty%2Fkernel%2Fstable.git gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation commit 1f1cc4566bd9dd8d3cf19965a4b6392143618536 upstream. 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. Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information") Signed-off-by: Lars-Peter Clausen Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 53ff25ac66d8c..44d976c238c16 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -837,7 +837,7 @@ 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];