On Wed, Feb 03, 2021 at 04:50:06PM +0000, Richard Fitzgerald wrote: > If a signed number field starts with a '-' the field width must be > 1, > or unlimited, to allow at least one digit after the '-'. > > This patch adds a check for this. If a signed field starts with '-' > and field_width == 1 the scanf will quit. > > It is ok for a signed number field to have a field width of 1 if it > starts with a digit. In that case the single digit can be converted.
Acked-by: Andy Shevchenko <[email protected]> > Signed-off-by: Richard Fitzgerald <[email protected]> > Reviewed-by: Petr Mladek <[email protected]> > --- > lib/vsprintf.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > index 3b53c73580c5..28bb26cd1f67 100644 > --- a/lib/vsprintf.c > +++ b/lib/vsprintf.c > @@ -3434,8 +3434,12 @@ int vsscanf(const char *buf, const char *fmt, va_list > args) > str = skip_spaces(str); > > digit = *str; > - if (is_sign && digit == '-') > + if (is_sign && digit == '-') { > + if (field_width == 1) > + break; > + > digit = *(str + 1); > + } > > if (!digit > || (base == 16 && !isxdigit(digit)) > -- > 2.20.1 > -- With Best Regards, Andy Shevchenko
