Messages in this thread | | | Date | Sat, 04 Feb 2006 03:38:16 +1030 | From | Glen Turner <> | Subject | Re: 8250 serial console fixes -- issue |
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Russell King wrote:
> My point stands - if the user can provide an arbitary string to printk, > they can fake any kernel message. That in itself is a security bug. > If there is an instance of that, then that's the real bug which would > need fixing. > > Once those bugs have been fixed, your claimed bug is also magically > fixed.
Hi Russell,
Thanks for the explanation of where the kernel should handle covert channels.
How about the other bugs reported by people who have used the Remote-Serial-Console-HOWTO:
- writing any text to an idle (DCD not asserted) modem still causes incoming calls to be hung up on. That's not good as sysadmins can't connect to systems with failing hardware.
[Note that modems really need the 'r' option, so it's fine to continue to write with DCD unasserted without the 'r' option.]
- the huge boot times with the 'r' option and an idle/ unconnected modem/terminal server. This is caused by the CTS timing out per character even when CTS is floating (CTS is not defined unless DSR is asserted). This basically makes the 'r' option impossible to use on production systems. Not using the 'r' option with a terminal server brings other problems (notably character loss problems when people paste a large number of characters into the SSH session through the terminal server to the remote host).
- writing LF CR rather than CR LF unfortunately causes issues with some terminals.
I'm really only the messenger here. I've collected bug reports from readers of the HOWTO and written a patch to address their experiences. I'm sure people with much more familiarity with the kernel can do it better.
Thanks, Glen
-- Glen Turner Tel: (08) 8303 3936 or +61 8 8303 3936 Australia's Academic & Research Network www.aarnet.edu.au - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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