tiny-printf: Handle NULL pointer argument to %s

A NULL pointer argument to %s causes a NULL pointer dereference in the
fixed width numerical printout code, since p is overwritten with NULL.
In case of %s width is 0. Check width before dereferencing the pointer.

Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
This commit is contained in:
Benedikt Spranger 2024-10-18 10:30:02 +02:00 committed by Eugen Hristev
parent 62224280d9
commit f0dab28915

View file

@ -312,7 +312,7 @@ static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
*info->bf = 0;
info->bf = p;
while (*info->bf++ && width > 0)
while (width > 0 && info->bf && *info->bf++)
width--;
while (width-- > 0)
info->putc(info, lz ? '0' : ' ');