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comics: Use libarchive to unpack documents [CVE-2023-44452].
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This commit eliminates the use of external commands for opening
comic documents, and uses libarchive instead.

Fixes:
CVE-2023-44452 - Linux Mint Xreader CBT File Parsing Argument
                 Injection Remote Code Execution Vulnerability.

Based on:
https://gitlab.gnome.org/GNOME/evince/-/commit/7b5ad18399b04cbfce02730d28baf30e9fc35b58

This vulnerability was discovered by:
Febin Mon Saji working with Trend Micro Zero Day Initiative
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@mtwebster @clefebvre
mtwebster authored and clefebvre committed Dec 12, 2023
1 parent 141f131 commit cd67888
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Showing 10 changed files with 995 additions and 790 deletions.
1,210 changes: 444 additions & 766 deletions backend/comics/comics-document.c
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9 changes: 3 additions & 6 deletions backend/comics/comics-document.h
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Original file line number Diff line number Diff line change
Expand Up @@ -16,9 +16,9 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

#ifndef __COMICS_DOCUMENT_H__
#define __COMICS_DOCUMENT_H__
#pragma once

#include "ev-macros.h"
#include "ev-document.h"

G_BEGIN_DECLS
Expand All @@ -30,9 +30,6 @@ G_BEGIN_DECLS
typedef struct _ComicsDocument ComicsDocument;

GType comics_document_get_type (void) G_GNUC_CONST;
GType register_evince_backend (GTypeModule *module);

G_MODULE_EXPORT GType register_xreader_backend (GTypeModule *module);

G_END_DECLS

#endif /* __COMICS_DOCUMENT_H__ */
4 changes: 2 additions & 2 deletions backend/comics/comicsdocument.xreader-backend.in
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
[Xreader Backend]
Module=comicsdocument
_TypeDescription=Comic Books
MimeType=application/x-cbr;application/x-cbz;application/x-cb7;application/x-cbt;application/vnd.comicbook+zip;
TypeDescription=Comic Books
MimeType=@COMICS_MIME_TYPES@;
323 changes: 323 additions & 0 deletions backend/comics/ev-archive.c
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Original file line number Diff line number Diff line change
@@ -0,0 +1,323 @@
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
/*
* Copyright (C) 2017, Bastien Nocera <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

#include "config.h"
#include "ev-archive.h"

#include <archive.h>
#include <archive_entry.h>
#include <gio/gio.h>

#define BUFFER_SIZE (64 * 1024)

struct _EvArchive {
GObject parent_instance;
EvArchiveType type;

/* libarchive */
struct archive *libar;
struct archive_entry *libar_entry;
};

G_DEFINE_TYPE(EvArchive, ev_archive, G_TYPE_OBJECT);

static void
ev_archive_finalize (GObject *object)
{
EvArchive *archive = EV_ARCHIVE (object);

switch (archive->type) {
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_clear_pointer (&archive->libar, archive_free);
break;
default:
break;
}

G_OBJECT_CLASS (ev_archive_parent_class)->finalize (object);
}

static void
ev_archive_class_init (EvArchiveClass *klass)
{
GObjectClass *object_class = (GObjectClass *) klass;

object_class->finalize = ev_archive_finalize;
}

EvArchive *
ev_archive_new (void)
{
return g_object_new (EV_TYPE_ARCHIVE, NULL);
}

static void
libarchive_set_archive_type (EvArchive *archive,
EvArchiveType archive_type)
{
archive->type = archive_type;
archive->libar = archive_read_new ();

if (archive_type == EV_ARCHIVE_TYPE_ZIP)
archive_read_support_format_zip (archive->libar);
else if (archive_type == EV_ARCHIVE_TYPE_7Z)
archive_read_support_format_7zip (archive->libar);
else if (archive_type == EV_ARCHIVE_TYPE_TAR)
archive_read_support_format_tar (archive->libar);
else if (archive_type == EV_ARCHIVE_TYPE_RAR) {
archive_read_support_format_rar (archive->libar);
archive_read_support_format_rar5 (archive->libar);
} else
g_assert_not_reached ();
}

EvArchiveType
ev_archive_get_archive_type (EvArchive *archive)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), EV_ARCHIVE_TYPE_NONE);

return archive->type;
}

gboolean
ev_archive_set_archive_type (EvArchive *archive,
EvArchiveType archive_type)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
g_return_val_if_fail (archive->type == EV_ARCHIVE_TYPE_NONE, FALSE);

switch (archive_type) {
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
libarchive_set_archive_type (archive, archive_type);
break;
default:
g_assert_not_reached ();
}

return TRUE;
}

gboolean
ev_archive_open_filename (EvArchive *archive,
const char *path,
GError **error)
{
int r;

g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);
g_return_val_if_fail (path != NULL, FALSE);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
r = archive_read_open_filename (archive->libar, path, BUFFER_SIZE);
if (r != ARCHIVE_OK) {
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
"Error opening archive: %s", archive_error_string (archive->libar));
return FALSE;
}
return TRUE;
}

return FALSE;
}

static gboolean
libarchive_read_next_header (EvArchive *archive,
GError **error)
{
while (1) {
int r;

r = archive_read_next_header (archive->libar, &archive->libar_entry);
if (r != ARCHIVE_OK) {
if (r != ARCHIVE_EOF)
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
"Error reading archive: %s", archive_error_string (archive->libar));
return FALSE;
}

if (archive_entry_filetype (archive->libar_entry) != AE_IFREG) {
g_debug ("Skipping '%s' as it's not a regular file",
archive_entry_pathname (archive->libar_entry));
continue;
}

g_debug ("At header for file '%s'", archive_entry_pathname (archive->libar_entry));

break;
}

return TRUE;
}

gboolean
ev_archive_read_next_header (EvArchive *archive,
GError **error)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
return libarchive_read_next_header (archive, error);
}

return FALSE;
}

gboolean
ev_archive_at_entry (EvArchive *archive)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);

return (archive->libar_entry != NULL);
}

const char *
ev_archive_get_entry_pathname (EvArchive *archive)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), NULL);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, NULL);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_return_val_if_fail (archive->libar_entry != NULL, NULL);
return archive_entry_pathname (archive->libar_entry);
}

return NULL;
}

gint64
ev_archive_get_entry_size (EvArchive *archive)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), -1);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, -1);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_return_val_if_fail (archive->libar_entry != NULL, -1);
return archive_entry_size (archive->libar_entry);
}

return -1;
}

gboolean
ev_archive_get_entry_is_encrypted (EvArchive *archive)
{
g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_return_val_if_fail (archive->libar_entry != NULL, -1);
return archive_entry_is_encrypted (archive->libar_entry);
}

return FALSE;
}

gssize
ev_archive_read_data (EvArchive *archive,
void *buf,
gsize count,
GError **error)
{
gssize r = -1;

g_return_val_if_fail (EV_IS_ARCHIVE (archive), -1);
g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, -1);

switch (archive->type) {
case EV_ARCHIVE_TYPE_NONE:
g_assert_not_reached ();
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_return_val_if_fail (archive->libar_entry != NULL, -1);
r = archive_read_data (archive->libar, buf, count);
if (r < 0) {
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
"Failed to decompress data: %s", archive_error_string (archive->libar));
}
break;
}

return r;
}

void
ev_archive_reset (EvArchive *archive)
{
g_return_if_fail (EV_IS_ARCHIVE (archive));
g_return_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE);

switch (archive->type) {
case EV_ARCHIVE_TYPE_RAR:
case EV_ARCHIVE_TYPE_ZIP:
case EV_ARCHIVE_TYPE_7Z:
case EV_ARCHIVE_TYPE_TAR:
g_clear_pointer (&archive->libar, archive_free);
libarchive_set_archive_type (archive, archive->type);
archive->libar_entry = NULL;
break;
default:
g_assert_not_reached ();
}
}

static void
ev_archive_init (EvArchive *archive)
{
}
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