From d042e5a66759cc2a8d0da946001ecfe004b38166 Mon Sep 17 00:00:00 2001 From: Hermann Semenov Date: Wed, 11 Jun 2025 16:43:31 +0300 Subject: [PATCH] os: fix missing NULL check for vpnprintf() Protect from NULL parameter to %s directive. See also: https://github.com/X11Libre/xserver/issues/36 Signed-off-by: Herman Semenov Signed-off-by: Enrico Weigelt, metux IT consult --- os/log.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/os/log.c b/os/log.c index 4af702b3b..60837b10d 100644 --- a/os/log.c +++ b/os/log.c @@ -449,8 +449,10 @@ vpnprintf(char *string, int size_in, const char *f, va_list args) case 's': string_arg = va_arg(args, char*); - for (i = 0; string_arg[i] != 0 && s_idx < size - 1 && s_idx < precision; i++) - string[s_idx++] = string_arg[i]; + if (string_arg) { + for (i = 0; string_arg[i] != 0 && s_idx < size - 1 && s_idx < precision; i++) + string[s_idx++] = string_arg[i]; + } break; case 'u':