From 364e569945c044fd18c70ee1bc851364534aef97 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Tue, 9 Jun 2020 16:12:01 -0300 Subject: Avoid calling 'fprintf' with NULL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Avoid undefined behavior in calls like «fprintf("%s", NULL)». ('lua_writestringerror' is implemented as 'fprintf', and 'lua_tostring' can return NULL if object is not a string.) --- ltests.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'ltests.c') diff --git a/ltests.c b/ltests.c index 7e6d8610..314505c3 100644 --- a/ltests.c +++ b/ltests.c @@ -73,8 +73,10 @@ static void badexit (const char *fmt, const char *s1, const char *s2) { static int tpanic (lua_State *L) { + const char *msg = lua_tostring(L, -1); + if (msg == NULL) msg = "error object is not a string"; return (badexit("PANIC: unprotected error in call to Lua API (%s)\n", - lua_tostring(L, -1), NULL), + msg, NULL), 0); /* do not return to Lua */ } -- cgit v1.2.3-55-g6feb