| Message ID | 20170824010404.9145-1-bjorn.andersson@linaro.org |
|---|---|
| State | Accepted |
| Commit | 08ab58d9de3eb8498ae0585001d0975e46217a39 |
| Headers | show |
On Wed, Aug 23, 2017 at 8:04 PM, Bjorn Andersson <bjorn.andersson@linaro.org> wrote: > 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. I guess ibmebus and macio had this bug for some time because I just copied those implementations. Applying both patches. Thanks. Rob
diff --git a/drivers/of/device.c b/drivers/of/device.c index 7cff599a9c6a..b58ca92934cb 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -262,6 +262,8 @@ ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) ssize_t sl = of_device_get_modalias(dev, str, len - 2); if (sl < 0) return sl; + if (sl > len - 2) + return -ENOMEM; str[sl++] = '\n'; str[sl] = 0;
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: 0634c2958927 ("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> --- drivers/of/device.c | 2 ++ 1 file changed, 2 insertions(+) -- 2.12.0