[PATCH, glibc] _hurd_socket_server: check for negative domains

[Pino Toscano]

Hi,

attached there is a patch for glibc to check for negative indexes in 
_hurd_socket_server(). This should avoid that calls to socket() or 
socketpair() with domain < 0 read/set OOB memory (and potentially 
crashing, like it happens when doing such calls using perl's socketpair 
for example), causing also a warning "task XXX deallocating an invalid 
port YYY, most probably a bug" in that situation.

-- 
Pino Toscano

Refuse negative socket domains right away; otherwise, it is possible to read
and set out-of-bounds locations of the `servers' array (returning the values
at those invalid memory locations), and even try to deallocate ports with
random values if the `dead' parameter is different than zero.

* hurd/hurdsock.c (_hurd_socket_server): Check for negative domains.
--- a/hurd/hurdsock.c
+++ b/hurd/hurdsock.c
@@ -47,6 +47,12 @@
 {
   socket_t server;
 
+  if (domain < 0)
+    {
+      errno = EAFNOSUPPORT;
+      return MACH_PORT_NULL;
+    }
+
   HURD_CRITICAL_BEGIN;
   __mutex_lock (&lock);
 

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