This repository was archived by the owner on Aug 2, 2025. It is now read-only.
This repository was archived by the owner on Aug 2, 2025. It is now read-only.
src/freon.c mishandles 3rd arg to open functions (mode) #3140
Description
the open signature is:
int open(const char *pathname, int flags, ...);
and mode is only passed in for certain flags (O_CREAT and O_TMPFILE), so trying to extract it otherwise is undefined behavior. you might get garbage, or you might crash.
freon.c assumes it's always passed in:
int open(const char *pathname, int flags, ...) {
if (!orig_open) preload_init();
va_list argp;
va_start(argp, flags);
mode_t mode = va_arg(argp, mode_t);
va_end(argp);same for open64.
you can do something instead like:
int open(const char *pathname, int flags, ...) {
if (!orig_open) preload_init();
mode_t mode = 0;
va_list argp;
va_start(argp, flags);
if (flags & (O_CREAT | O_TMPFILE))
mode = va_arg(argp, mode_t);
va_end(argp);