[Linux-HA] File descriptors in heartbeat V1

[Simon Rowe]

On Wednesday 26 Oct 2005 15:02, Alan Robertson wrote:

> Well... It's only a security problem if they read or write them.  Only
> the appropriate child processes read or write them.

If the child process doesn't need them then they should be closed.

> It's only a resource problem if they were different file descriptors.
> In the kernel, they're all the same file descriptor - so no additional
> resources are consumed.

I was thinking more that it reduces the number of fds a process could open. 
This isn't an issue in reality because the child processes only need a few 
fds.

> It wouldn't be so hard to close the _media_ file descriptors that aren't
> needed.  But, I don't know of any attacks that can take advantage of
> them being open.

You really should close those fds that aren't required, not knowing of any 
existing attacks isn't a good enough protection. There's nothing to stop 
someone discovering a vulnerability in the serial plugin and then using to 
launch a DOS via the ethernet fd.