coda: Restrict coda messages to the initial pid namespace

Remove the slight chance that pids in coda messages will be
interpreted in the wrong pid namespace.

- Explicitly send all pids in coda messages in the initial pid
  namespace.
- Only allow mounts from processes in the initial pid namespace.
- Only allow processes in the initial pid namespace to open the coda
  character device to communicate with coda.

Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/coda/upcall.c b/fs/coda/upcall.c
index 0c68fd31fbf2..5c6d2cd6ee86 100644
--- a/fs/coda/upcall.c
+++ b/fs/coda/upcall.c
@@ -50,8 +50,8 @@ static void *alloc_upcall(int opcode, int size)
                 return ERR_PTR(-ENOMEM);
 
         inp->ih.opcode = opcode;
-        inp->ih.pid = current->pid;
-        inp->ih.pgid = task_pgrp_nr(current);
+        inp->ih.pid = task_pid_nr_ns(current, &init_pid_ns);
+        inp->ih.pgid = task_pgrp_nr_ns(current, &init_pid_ns);
         inp->ih.uid = current_fsuid();
 
         return (void*)inp;