On Tue, Apr 21, 2015 at 09:25:41PM +0200, Heinrich Schuchardt wrote: > Hello Peter, > > thanks for reviewing. > > On 21.04.2015 03:32, Peter Chen wrote: > > On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: > >> A string written by the user may not be zero terminated. > >> > >> sscanf may read memory beyond the buffer if no zero byte > >> is found. > >> > >> Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx> > >> --- > >> drivers/usb/chipidea/debug.c | 6 +++++- > >> 1 file changed, 5 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c > >> index dfb05ed..ef08af3 100644 > >> --- a/drivers/usb/chipidea/debug.c > >> +++ b/drivers/usb/chipidea/debug.c > >> @@ -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; > > > > Any reasons to change above? > > Otherwise we would have two lines with the term > min_t(size_t, sizeof(buf) - 1, count). Sorry, two lines of min_t(..)? Why I can't find it? > > This would make the code harder to read. > > >> > >> + /* sscanf requires a zero terminated string */ > >> + buf[count] = 0; > >> + > > > > I prefer using '\0' > > If you confirm the rest of the patch is ok, I will send an updated patch. > > Best regards > > Heinrich > > > > >> if (sscanf(buf, "%u", &mode) != 1) > >> return -EINVAL; > >> > -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
