[PATCH glibc] _hurd_intr_rpc_mach_msg: handle message iteration correctly.

[Flavio Cruz]

The `ty` pointer is only set at the end of the loop so that
`msgtl_header.msgt_inline` and `msgtl_header.msgt_deallocate` remain
valid. Also, when deallocating memory, we use the length from the
message directly rather than hard coding mach_port_t since we want to
deallocate any kind of OOL data.
---
 hurd/intr-msg.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c
index 98f588f2..737bfe0f 100644
--- a/hurd/intr-msg.c
+++ b/hurd/intr-msg.c
@@ -186,12 +186,14 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
              mach_msg_type_size_t size;
              mach_msg_type_number_t number;
 
-             inline void clean_ports (mach_port_t *ports, int dealloc)
+             inline void clean_ports_and_memory (char *data, const vm_size_t 
length,
+                                               int dealloc)
                {
                  mach_msg_type_number_t i;
                  switch (name)
                    {
                    case MACH_MSG_TYPE_MOVE_SEND:
+                     mach_port_t *ports = (mach_port_t *) data;
                      for (i = 0; i < number; i++)
                        __mach_port_deallocate (__mach_task_self (), *ports++);
                      if (ty->msgtl_header.msgt_longform)
@@ -207,40 +209,38 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
                        assert (! "unexpected port type in interruptible RPC");
                    }
                  if (dealloc)
-                   __vm_deallocate (__mach_task_self (),
-                                    (vm_address_t) ports,
-                                    number * sizeof (mach_port_t));
+                   __vm_deallocate (__mach_task_self (), (vm_address_t) data, 
length);
                }
 
+             char *data;
              if (ty->msgtl_header.msgt_longform)
                {
                  name = ty->msgtl_name;
                  size = ty->msgtl_size;
                  number = ty->msgtl_number;
-                 ty = (void *) ty + sizeof (mach_msg_type_long_t);
+                 data = (char *) ty + sizeof (mach_msg_type_long_t);
                }
              else
                {
                  name = ty->msgtl_header.msgt_name;
                  size = ty->msgtl_header.msgt_size;
                  number = ty->msgtl_header.msgt_number;
-                 ty = (void *) ty + sizeof (mach_msg_type_t);
+                 data = (char *) ty + sizeof (mach_msg_type_t);
                }
 
+             const vm_size_t length = ((number * size) + 7) >> 3;
              if (ty->msgtl_header.msgt_inline)
                {
                  /* Calculate length of data in bytes.  */
-                 const vm_size_t length = ((number * size) + 7) >> 3;
-                 clean_ports ((void *) ty, 0);
+                 clean_ports_and_memory (data, length, 0);
                  /* Move to the next argument.  */
-                 ty = (void *) PTR_ALIGN_UP ((char *) ty + length,
-                     __alignof__ (uintptr_t));
+                 ty = (void *) PTR_ALIGN_UP (data + length, __alignof__ 
(uintptr_t));
                }
              else
                {
-                 clean_ports (*(void **) ty,
+                 clean_ports_and_memory (*(void **) data, length,
                               ty->msgtl_header.msgt_deallocate);
-                 ty = (void *) ty + sizeof (void *);
+                 ty = (void *) data + sizeof (void *);
                }
            }
 #else  /* Untyped Mach IPC flavor. */
-- 
2.39.2