Changeset 96582 in vbox for trunk/src/VBox/Runtime/r3

Timestamp:

Sep 2, 2022 3:22:35 PM (2 years ago)

Author:

vboxsync

Message:

IPRT: Darwin's libpthread doesn't validate pthread_getspecific input, so we have to do that for them to avoid misbehaviour if called before initialization. bugref:10261

File:

• trunk/src/VBox/Runtime/r3/posix/thread-posix.cpp (modified) (1 diff)

trunk/src/VBox/Runtime/r3/posix/thread-posix.cpp

@@ -664 +664 @@
 RTDECL(RTTHREAD) RTThreadSelf(void)
 {
-    PRTTHREADINT pThread = (PRTTHREADINT)pthread_getspecific(g_SelfKey);
     /** @todo import alien threads? */
-    return pThread;
+#if defined(RT_OS_DARWIN)
+    /* On darwin, there seems to be input checking with pthread_getspecific.
+       So, we must prevent using g_SelfKey before rtThreadNativeInit has run,
+       otherwise we might crash or starting working with total garbage pointer
+       values here (see _os_tsd_get_direct in znu/libsyscall/os/tsd.h).
+
+       Now, since the init value is a "negative" one, we just have to check
+       that it's positive or zero before calling the API. */
+    if (RT_LIKELY((intptr_t)g_SelfKey >= 0))
+        return (PRTTHREADINT)pthread_getspecific(g_SelfKey);
+    return NIL_RTTHREAD;
+#else
+    return (PRTTHREADINT)pthread_getspecific(g_SelfKey);
+#endif
 }