leaking_addresses: skip all /proc/PID except /proc/1

When the system is idle it is likely that most files under /proc/PID
will be identical for various processes.  Scanning _all_ the PIDs under
/proc is unnecessary and implies that we are thoroughly scanning /proc.
This is _not_ the case because there may be ways userspace can trigger
creation of /proc files that leak addresses but were not present during
a scan.  For these two reasons we should exclude all PID directories
under /proc except '1/'

Exclude all /proc/PID except /proc/1.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
This commit is contained in:
Tobin C. Harding 2018-02-27 15:02:57 +11:00
parent 5e4bac34ed
commit 472c9e1085

View File

@ -10,6 +10,14 @@
# Use --debug to output path before parsing, this is useful to find files that
# cause the script to choke.
#
# When the system is idle it is likely that most files under /proc/PID will be
# identical for various processes. Scanning _all_ the PIDs under /proc is
# unnecessary and implies that we are thoroughly scanning /proc. This is _not_
# the case because there may be ways userspace can trigger creation of /proc
# files that leak addresses but were not present during a scan. For these two
# reasons we exclude all PID directories under /proc except '1/'
use warnings;
use strict;
use POSIX;
@ -472,6 +480,10 @@ sub walk
my $path = "$pwd/$file";
next if (-l $path);
# skip /proc/PID except /proc/1
next if (($path =~ /^\/proc\/[0-9]+$/) &&
($path !~ /^\/proc\/1$/));
next if (skip($path));
if (-d $path) {