Revision 9c1c2b35f1d94de8325344c2777d7ee67492db3b authored by Jeff Layton on 03 April 2019, 17:16:01 UTC, committed by Ilya Dryomov on 21 January 2020, 18:02:37 UTC
Currently, we just assume that it will stick around by virtue of the submitter's reference, but later patches will allow the syscall to return early and we can't rely on that reference at that point. While I'm not aware of any reports of it, Xiubo pointed out that this may fix a use-after-free. If the wait for a reply times out or is canceled via signal, and then the reply comes in after the syscall returns, the client can end up trying to access r_parent without a reference. Take an extra reference to the inode when setting r_parent and release it when releasing the request. Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
1 parent def9d27
cleanfile
#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
#
# Clean a text file -- or directory of text files -- of stealth whitespace.
# WARNING: this can be a highly destructive operation. Use with caution.
#
use warnings;
use bytes;
use File::Basename;
# Default options
$max_width = 79;
# Clean up space-tab sequences, either by removing spaces or
# replacing them with tabs.
sub clean_space_tabs($)
{
no bytes; # Tab alignment depends on characters
my($li) = @_;
my($lo) = '';
my $pos = 0;
my $nsp = 0;
my($i, $c);
for ($i = 0; $i < length($li); $i++) {
$c = substr($li, $i, 1);
if ($c eq "\t") {
my $npos = ($pos+$nsp+8) & ~7;
my $ntab = ($npos >> 3) - ($pos >> 3);
$lo .= "\t" x $ntab;
$pos = $npos;
$nsp = 0;
} elsif ($c eq "\n" || $c eq "\r") {
$lo .= " " x $nsp;
$pos += $nsp;
$nsp = 0;
$lo .= $c;
$pos = 0;
} elsif ($c eq " ") {
$nsp++;
} else {
$lo .= " " x $nsp;
$pos += $nsp;
$nsp = 0;
$lo .= $c;
$pos++;
}
}
$lo .= " " x $nsp;
return $lo;
}
# Compute the visual width of a string
sub strwidth($) {
no bytes; # Tab alignment depends on characters
my($li) = @_;
my($c, $i);
my $pos = 0;
my $mlen = 0;
for ($i = 0; $i < length($li); $i++) {
$c = substr($li,$i,1);
if ($c eq "\t") {
$pos = ($pos+8) & ~7;
} elsif ($c eq "\n") {
$mlen = $pos if ($pos > $mlen);
$pos = 0;
} else {
$pos++;
}
}
$mlen = $pos if ($pos > $mlen);
return $mlen;
}
$name = basename($0);
@files = ();
while (defined($a = shift(@ARGV))) {
if ($a =~ /^-/) {
if ($a eq '-width' || $a eq '-w') {
$max_width = shift(@ARGV)+0;
} else {
print STDERR "Usage: $name [-width #] files...\n";
exit 1;
}
} else {
push(@files, $a);
}
}
foreach $f ( @files ) {
print STDERR "$name: $f\n";
if (! -f $f) {
print STDERR "$f: not a file\n";
next;
}
if (!open(FILE, '+<', $f)) {
print STDERR "$name: Cannot open file: $f: $!\n";
next;
}
binmode FILE;
# First, verify that it is not a binary file; consider any file
# with a zero byte to be a binary file. Is there any better, or
# additional, heuristic that should be applied?
$is_binary = 0;
while (read(FILE, $data, 65536) > 0) {
if ($data =~ /\0/) {
$is_binary = 1;
last;
}
}
if ($is_binary) {
print STDERR "$name: $f: binary file\n";
next;
}
seek(FILE, 0, 0);
$in_bytes = 0;
$out_bytes = 0;
$blank_bytes = 0;
@blanks = ();
@lines = ();
$lineno = 0;
while ( defined($line = <FILE>) ) {
$lineno++;
$in_bytes += length($line);
$line =~ s/[ \t\r]*$//; # Remove trailing spaces
$line = clean_space_tabs($line);
if ( $line eq "\n" ) {
push(@blanks, $line);
$blank_bytes += length($line);
} else {
push(@lines, @blanks);
$out_bytes += $blank_bytes;
push(@lines, $line);
$out_bytes += length($line);
@blanks = ();
$blank_bytes = 0;
}
$l_width = strwidth($line);
if ($max_width && $l_width > $max_width) {
print STDERR
"$f:$lineno: line exceeds $max_width characters ($l_width)\n";
}
}
# Any blanks at the end of the file are discarded
if ($in_bytes != $out_bytes) {
# Only write to the file if changed
seek(FILE, 0, 0);
print FILE @lines;
if ( !defined($where = tell(FILE)) ||
!truncate(FILE, $where) ) {
die "$name: Failed to truncate modified file: $f: $!\n";
}
}
close(FILE);
}
Computing file changes ...