Commit bd5fb0ae authored Apr 28, 2015 by Heinrich Schuchardt Committed by Peter Chen May 06, 2015

usb: chipidea: debug: avoid out of bound read



A string written by the user may not be zero terminated.

sscanf may read memory beyond the buffer if no zero byte
is found.

For testing build with CONFIG_USB_CHIPIDEA=y, CONFIG_USB_CHIPIDEA_DEBUG=y.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>

parent 0d3bba02

drivers/usb/chipidea/debug.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file file, const char __user ubuf,
		char buf[32];
		int ret;

		if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
		count = min_t(size_t, sizeof(buf) - 1, count);
		if (copy_from_user(buf, ubuf, count))
		return -EFAULT;

		/* sscanf requires a zero terminated string */
		buf[count] = '\0';

		if (sscanf(buf, "%u", &mode) != 1)
		return -EINVAL;