From b0de59b5733d18b0d1974a060860a8b5c1b36a2e Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Fri, 15 Feb 2013 15:25:05 +0100 Subject: [PATCH] TTY: do not update atime/mtime on read/write On http://vladz.devzero.fr/013_ptmx-timing.php, we can see how to find out length of a password using timestamps of /dev/ptmx. It is documented in "Timing Analysis of Keystrokes and Timing Attacks on SSH". To avoid that problem, do not update time when reading from/writing to a TTY. I am afraid of regressions as this is a behavior we have since 0.97 and apps may expect the time to be current, e.g. for monitoring whether there was a change on the TTY. Now, there is no change. So this would better have a lot of testing before it goes upstream. References: CVE-2013-0160 Signed-off-by: Jiri Slaby Cc: stable # after 3.9 is out Signed-off-by: Greg Kroah-Hartman --- Reading git-format-patch failed