Commit 08ab58d9 authored Aug 23, 2017 by Bjorn Andersson Committed by Rob Herring Aug 24, 2017

of/device: Prevent buffer overflow in of_device_modalias()



As of_device_get_modalias() returns the number of bytes that would have
been written to the target string, regardless of how much did fit in the
buffer, it's possible that the returned index points beyond the buffer
passed to of_device_modalias() - causing memory beyond the buffer to be
null terminated.

Fixes: 0634c295 ("of: Add function for generating a DT modalias with a newline")
Cc: Rob Herring <robh@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>

parent 3cffda25

drivers/of/device.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -257,6 +257,8 @@ ssize_t of_device_modalias(struct device dev, char str, ssize_t len)
	ssize_t sl = of_device_get_modalias(dev, str, len - 2);		ssize_t sl = of_device_get_modalias(dev, str, len - 2);
	if (sl < 0)		if (sl < 0)
	return sl;		return sl;
			if (sl > len - 2)
			return -ENOMEM;

	str[sl++] = '\n';		str[sl++] = '\n';
	str[sl] = 0;		str[sl] = 0;