[PATCH 1/1] console: file should always be non-negative

[Simon Glass]

Hi Heinrich,

On Sat, 29 Oct 2022 at 20:47, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
>
>
> On 10/30/22 02:43, Simon Glass wrote:
> > Hi Heinrich,
> >
> > On Sat, 22 Oct 2022 at 03:49, Heinrich Schuchardt
> > <heinrich.schuchardt at canonical.com> wrote:
> >>
> >> We use the parameter file in console function to choose from an array after
> >> checking against MAX_FILES but we never check if the value of file is
> >> negative.
> >>
> >> Running ./u-boot -T -l and issuing the poweroff command has resulted in
> >> crashes because
> >>
> >> os_exit() results in std::ostream::flush() calling U-Boot's fflush with
> >> file being a pointer which when converted to int may be represented by a
> >> negative number.
> >>
> >> This shows that checking against MAX_FILES is not enough we have to ensure
> >> that the file argument is always positive.
> >>
> >> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> >> ---
> >>   common/console.c | 10 +++++-----
> >>   1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > How about changing the 'file' parameter to a uint? It seems that this
> > is what it is supposed to be, from your checks.
>
> As we support only 3 values the variable type should have been defined
> as an enum.
>
> Changing the parameter type would have meant to look at all callers and
> check if the value of file is stored in a variable and replace that
> variable type too.
>
> I just went for the least invasive change.

Well I don't really mind.

Reviewed-by: Simon Glass <sjg at chromium.org>