54013: add a range check on signal numbers passed to trap

Author: Oliver Kiddle

ChangeLog

@@ -1,5 +1,8 @@
 2025-10-31  Oliver Kiddle  <[email protected]>
 
+	* 54013: Src/builtin.c, Src/jobs.c: add a range check on signal
+	numbers passed to trap
+
 	* 54012: Src/subst.c: fix use of out of scope array variable
 
 	* 54007: Src/exec.c, Src/hist.c, Src/init.c, Src/jobs.c, Src/module.c,

Src/builtin.c

@@ -7428,6 +7428,14 @@ bin_trap(char *name, char **argv, UNUSED(Options ops), UNUSED(int func))
 	return 1;
     }
 
+    if (!*argv) {
+	if (idigit(*arg) || !strncmp(arg, "SIG", 3))
+	    zwarnnam(name, "undefined signal: %s", arg);
+	else
+	    zwarnnam(name, "signal expected");
+	return 1;
+    }
+
     /* set traps */
     for (; *argv; argv++) {
 	Eprog t;

Src/jobs.c

@@ -3054,7 +3054,11 @@ getsigidx(const char *s)
 
     /* check for a signal specified by number */
     x = atoi(s);
-    if (idigit(*s) && x >= 0)
+    if (idigit(*s) && x >= 0 && (x < VSIGCOUNT
+#if defined(SIGRTMIN) && defined(SIGRTMAX)
+	|| (x >= SIGRTMIN && x <= SIGRTMAX)
+#endif
+	))
 	return SIGIDX(x);
 
     /* search for signal by name */