Re: [PATCH net-next] nfnetlink_queue: enable PID info retrieval

On 06/09/2016 11:35 PM, Florian Westphal wrote:

Saeed Mahameed [off-list ref] wrote:

quoted

index a1bd161..67de200 100644

--- a/net/socket.c
+++ b/net/socket.c

@@ -382,6 +382,7 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
  	}

  	sock->file = file;
+	file->f_owner.sock_pid  = find_get_pid(task_pid_nr(current));
  	file->f_flags = O_RDWR | (flags & O_NONBLOCK);
  	file->private_data = sock;
  	return file;

This looks like this leaks sock_pid reference...?

(find_get_pid -> get_pid -> atomic_inc() , I don't see a put_pid in the
  patch)

Can't comment further than this since I'm not familiar with vfs; e.g.
I can't say if fown_struct is right place or not, or if this approach
even works when creating process has exited after fork, etc.

Or ... if you xmit the fd via unix domain socket to a different process
and initial owner terminates, which should give you invalid information
then; afaik, this would just increase struct file's refcnt and hand out
an unused fdnum ( get_unused_fd_flags() + fd_install(), etc).
For extending 'struct fown_struct', you probably also need to Cc fs folks.