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.
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Reviewed-by: Petr Mladek pmladek@suse.com --- 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))