From: Jiri Slaby Date: Fri, 15 Feb 2013 14:25:05 +0000 (+0100) Subject: TTY: do not update atime/mtime on read/write X-Git-Tag: v3.2.45~45 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c29ad805df8c54a9f5d74c66bf5d4a2d449bd99a;p=pandora-kernel.git TTY: do not update atime/mtime on read/write commit b0de59b5733d18b0d1974a060860a8b5c1b36a2e upstream. 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed