Fixed bug: invalid mode can crash 'io.popen'

This commit is contained in:
Roberto Ierusalimschy
2020-07-15 16:01:03 -03:00
parent e1d8770f12
commit 1ecfbfa1a1
2 changed files with 22 additions and 0 deletions

View File

@@ -52,6 +52,12 @@ static int l_checkmode (const char *mode) {
** =======================================================
*/
#if !defined(l_checkmodep)
/* By default, Lua accepts only "r" or "w" as mode */
#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
#endif
#if !defined(l_popen) /* { */
#if defined(LUA_USE_POSIX) /* { */
@@ -279,6 +285,7 @@ static int io_popen (lua_State *L) {
const char *filename = luaL_checkstring(L, 1);
const char *mode = luaL_optstring(L, 2, "r");
LStream *p = newprefile(L);
luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
p->f = l_popen(L, filename, mode);
p->closef = &io_pclose;
return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;