psxbios: Fix out-of-bounds issue.

Make sure to return 0xff is no TCBs are available.
Thanks senquack for the proper fix.

diff --git a/libpcsxcore/psxbios.c b/libpcsxcore/psxbios.c
index 9341b0d..5bff23e 100644 (file)
--- a/libpcsxcore/psxbios.c
+++ b/libpcsxcore/psxbios.c
@@ -1667,8 +1667,20 @@ void psxBios_OpenTh() { // 0e
        int th;
 
        for (th=1; th<8; th++)
+       {
                if (Thread[th].status == 0) break;
 
+       }
+       if (th == 8) {
+               // Feb 2019 - Added out-of-bounds fix caught by cppcheck:
+               // When no free TCB is found, return 0xffffffff according to Nocash doc.
+#ifdef PSXBIOS_LOG
+               PSXBIOS_LOG("\t%s() WARNING! No Free TCBs found!\n", __func__);
+#endif
+               v0 = 0xffffffff;
+               pc0 = ra;
+               return;
+       }
 #ifdef PSXBIOS_LOG
        PSXBIOS_LOG("psxBios_%s: %x\n", biosB0n[0x0e], th);
 #endif