leaking_addresses: add timeout on file read

Currently script can stall if we read certain files (like
/proc/kmsg). While we have a mechanism to skip these files once they are
discovered it would be nice to not stall on as yet undiscovered files of
this kind.

Set a timer before each file is parsed, warn user if timer expires.

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <me@tobin.cc>
This commit is contained in:
Tobin C. Harding 2017-11-09 15:37:06 +11:00
parent 62139c1242
commit dd98c252ae

View File

@ -29,6 +29,9 @@ my $V = '0.01';
# Directories to scan.
my @DIRS = ('/proc', '/sys');
# Timer for parsing each file, in seconds.
my $TIMEOUT = 10;
# Script can only grep for kernel addresses on the following architectures. If
# your architecture is not listed here and has a grep'able kernel address please
# consider submitting a patch.
@ -284,6 +287,23 @@ sub skip_parse
return skip($path, \@skip_parse_files_abs, \@skip_parse_files_any);
}
sub timed_parse_file
{
my ($file) = @_;
eval {
local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required.
alarm $TIMEOUT;
parse_file($file);
alarm 0;
};
if ($@) {
die unless $@ eq "alarm\n"; # Propagate unexpected errors.
printf STDERR "timed out parsing: %s\n", $file;
}
}
sub parse_file
{
my ($file) = @_;
@ -335,7 +355,7 @@ sub walk
if (-d $path) {
push @dirs, $path;
} else {
parse_file($path);
timed_parse_file($path);
}
}
}