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anonymous /CVE-2014-0475.patch.txt
Created Jul 11, 2014

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CVE-2014-0475.patch
From 176fc6c7ddec8d93468f9b790d39dcab6d41b1a6 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Mon, 12 May 2014 15:24:12 +0200
Subject: [PATCH] _nl_find_locale: Improve handling of crafted locale names [BZ #17137]
Prevent directory traversal in locale-related environment variables
(CVE-2014-0475).
(cherry picked from commit 4e8f95a0df7c2300b830ec12c0ae1e161bc8a8a3)
Conflicts:
NEWS
localedata/Makefile
---
ChangeLog | 9 ++
NEWS | 11 ++-
locale/findlocale.c | 74 +++++++++++++---
localedata/ChangeLog | 6 ++
localedata/Makefile | 2 +-
localedata/tst-setlocale3.c | 203 +++++++++++++++++++++++++++++++++++++++++++
6 files changed, 290 insertions(+), 15 deletions(-)
create mode 100644 localedata/tst-setlocale3.c
diff --git a/locale/findlocale.c b/locale/findlocale.c
index 0c42b99..faeee61 100644
--- a/locale/findlocale.c
+++ b/locale/findlocale.c
@@ -17,6 +17,7 @@
<http://www.gnu.org/licenses/>. */
#include <assert.h>
+#include <errno.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
@@ -57,6 +58,45 @@ struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST];
const char _nl_default_locale_path[] attribute_hidden = LOCALEDIR;
+/* Checks if the name is actually present, that is, not NULL and not
+ empty. */
+static inline int
+name_present (const char *name)
+{
+ return name != NULL && name[0] != '\0';
+}
+
+/* Checks that the locale name neither extremely long, nor contains a
+ ".." path component (to prevent directory traversal). */
+static inline int
+valid_locale_name (const char *name)
+{
+ /* Not set. */
+ size_t namelen = strlen (name);
+ /* Name too long. The limit is arbitrary and prevents stack overflow
+ issues later. */
+ if (__glibc_unlikely (namelen > 255))
+ return 0;
+ /* Directory traversal attempt. */
+ static const char slashdot[4] = {'/', '.', '.', '/'};
+ if (__glibc_unlikely (memmem (name, namelen,
+ slashdot, sizeof (slashdot)) != NULL))
+ return 0;
+ if (namelen == 2 && __glibc_unlikely (name[0] == '.' && name [1] == '.'))
+ return 0;
+ if (namelen >= 3
+ && __glibc_unlikely (((name[0] == '.'
+ && name[1] == '.'
+ && name[2] == '/')
+ || (name[namelen - 3] == '/'
+ && name[namelen - 2] == '.'
+ && name[namelen - 1] == '.'))))
+ return 0;
+ /* If there is a slash in the name, it must start with one. */
+ if (__glibc_unlikely (memchr (name, '/', namelen) != NULL) && name[0] != '/')
+ return 0;
+ return 1;
+}
struct __locale_data *
internal_function
@@ -65,7 +105,7 @@ _nl_find_locale (const char *locale_path, size_t locale_path_len,
{
int mask;
/* Name of the locale for this category. */
- char *loc_name;
+ char *loc_name = (char *) *name;
const char *language;
const char *modifier;
const char *territory;
@@ -73,31 +113,39 @@ _nl_find_locale (const char *locale_path, size_t locale_path_len,
const char *normalized_codeset;
struct loaded_l10nfile *locale_file;
- if ((*name)[0] == '\0')
+ if (loc_name[0] == '\0')
{
/* The user decides which locale to use by setting environment
variables. */
- *name = getenv ("LC_ALL");
- if (*name == NULL || (*name)[0] == '\0')
- *name = getenv (_nl_category_names.str
+ loc_name = getenv ("LC_ALL");
+ if (!name_present (loc_name))
+ loc_name = getenv (_nl_category_names.str
+ _nl_category_name_idxs[category]);
- if (*name == NULL || (*name)[0] == '\0')
- *name = getenv ("LANG");
+ if (!name_present (loc_name))
+ loc_name = getenv ("LANG");
+ if (!name_present (loc_name))
+ loc_name = (char *) _nl_C_name;
}
- if (*name == NULL || (*name)[0] == '\0'
- || (__builtin_expect (__libc_enable_secure, 0)
- && strchr (*name, '/') != NULL))
- *name = (char *) _nl_C_name;
+ /* We used to fall back to the C locale if the name contains a slash
+ character '/', but we now check for directory traversal in
+ valid_locale_name, so this is no longer necessary. */
- if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
- || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
+ if (__builtin_expect (strcmp (loc_name, _nl_C_name), 1) == 0
+ || __builtin_expect (strcmp (loc_name, _nl_POSIX_name), 1) == 0)
{
/* We need not load anything. The needed data is contained in
the library itself. */
*name = (char *) _nl_C_name;
return _nl_C[category];
}
+ else if (!valid_locale_name (loc_name))
+ {
+ __set_errno (EINVAL);
+ return NULL;
+ }
+
+ *name = loc_name;
/* We really have to load some data. First we try the archive,
but only if there was no LOCPATH environment variable specified. */
diff --git a/localedata/Makefile b/localedata/Makefile
index 7d157bf..9daa470 100644
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -77,7 +77,7 @@ locale_test_suite := tst_iswalnum tst_iswalpha tst_iswcntrl \
tests = $(locale_test_suite) tst-digits tst-setlocale bug-iconv-trans \
tst-leaks tst-mbswcs6 tst-xlocale1 tst-xlocale2 bug-usesetlocale \
- tst-strfmon1 tst-sscanf bug-setlocale1 tst-setlocale2
+ tst-strfmon1 tst-sscanf bug-setlocale1 tst-setlocale2 tst-setlocale3
tests-static = bug-setlocale1-static
tests += $(tests-static)
ifeq (yes,$(build-shared))
diff --git a/localedata/tst-setlocale3.c b/localedata/tst-setlocale3.c
new file mode 100644
index 0000000..e3b21a9
--- /dev/null
+++ b/localedata/tst-setlocale3.c
@@ -0,0 +1,203 @@
+/* Regression test for setlocale invalid environment variable handling.
+ Copyright (C) 2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* The result of setlocale may be overwritten by subsequent calls, so
+ this wrapper makes a copy. */
+static char *
+setlocale_copy (int category, const char *locale)
+{
+ const char *result = setlocale (category, locale);
+ if (result == NULL)
+ return NULL;
+ return strdup (result);
+}
+
+static char *de_locale;
+
+static void
+setlocale_fail (const char *envstring)
+{
+ setenv ("LC_CTYPE", envstring, 1);
+ if (setlocale (LC_CTYPE, "") != NULL)
+ {
+ printf ("unexpected setlocale success for \"%s\" locale\n", envstring);
+ exit (1);
+ }
+ const char *newloc = setlocale (LC_CTYPE, NULL);
+ if (strcmp (newloc, de_locale) != 0)
+ {
+ printf ("failed setlocale call \"%s\" changed locale to \"%s\"\n",
+ envstring, newloc);
+ exit (1);
+ }
+}
+
+static void
+setlocale_success (const char *envstring)
+{
+ setenv ("LC_CTYPE", envstring, 1);
+ char *newloc = setlocale_copy (LC_CTYPE, "");
+ if (newloc == NULL)
+ {
+ printf ("setlocale for \"%s\": %m\n", envstring);
+ exit (1);
+ }
+ if (strcmp (newloc, de_locale) == 0)
+ {
+ printf ("setlocale with LC_CTYPE=\"%s\" left locale at \"%s\"\n",
+ envstring, de_locale);
+ exit (1);
+ }
+ if (setlocale (LC_CTYPE, de_locale) == NULL)
+ {
+ printf ("restoring locale \"%s\" with LC_CTYPE=\"%s\": %m\n",
+ de_locale, envstring);
+ exit (1);
+ }
+ char *newloc2 = setlocale_copy (LC_CTYPE, newloc);
+ if (newloc2 == NULL)
+ {
+ printf ("restoring locale \"%s\" following \"%s\": %m\n",
+ newloc, envstring);
+ exit (1);
+ }
+ if (strcmp (newloc, newloc2) != 0)
+ {
+ printf ("representation of locale \"%s\" changed from \"%s\" to \"%s\"",
+ envstring, newloc, newloc2);
+ exit (1);
+ }
+ free (newloc);
+ free (newloc2);
+
+ if (setlocale (LC_CTYPE, de_locale) == NULL)
+ {
+ printf ("restoring locale \"%s\" with LC_CTYPE=\"%s\": %m\n",
+ de_locale, envstring);
+ exit (1);
+ }
+}
+
+/* Checks that a known-good locale still works if LC_ALL contains a
+ value which should be ignored. */
+static void
+setlocale_ignore (const char *to_ignore)
+{
+ const char *fr_locale = "fr_FR.UTF-8";
+ setenv ("LC_CTYPE", fr_locale, 1);
+ char *expected_locale = setlocale_copy (LC_CTYPE, "");
+ if (expected_locale == NULL)
+ {
+ printf ("setlocale with LC_CTYPE=\"%s\" failed: %m\n", fr_locale);
+ exit (1);
+ }
+ if (setlocale (LC_CTYPE, de_locale) == NULL)
+ {
+ printf ("failed to restore locale: %m\n");
+ exit (1);
+ }
+ unsetenv ("LC_CTYPE");
+
+ setenv ("LC_ALL", to_ignore, 1);
+ setenv ("LC_CTYPE", fr_locale, 1);
+ const char *actual_locale = setlocale (LC_CTYPE, "");
+ if (actual_locale == NULL)
+ {
+ printf ("setlocale with LC_ALL, LC_CTYPE=\"%s\" failed: %m\n",
+ fr_locale);
+ exit (1);
+ }
+ if (strcmp (actual_locale, expected_locale) != 0)
+ {
+ printf ("setlocale under LC_ALL failed: got \"%s\", expected \"%s\"\n",
+ actual_locale, expected_locale);
+ exit (1);
+ }
+ unsetenv ("LC_CTYPE");
+ setlocale_success (fr_locale);
+ unsetenv ("LC_ALL");
+ free (expected_locale);
+}
+
+static int
+do_test (void)
+{
+ /* The glibc test harness sets this environment variable
+ uncondionally. */
+ unsetenv ("LC_ALL");
+
+ de_locale = setlocale_copy (LC_CTYPE, "de_DE.UTF-8");
+ if (de_locale == NULL)
+ {
+ printf ("setlocale (LC_CTYPE, \"de_DE.UTF-8\"): %m\n");
+ return 1;
+ }
+ setlocale_success ("C");
+ setlocale_success ("en_US.UTF-8");
+ setlocale_success ("/en_US.UTF-8");
+ setlocale_success ("//en_US.UTF-8");
+ setlocale_ignore ("");
+
+ setlocale_fail ("does-not-exist");
+ setlocale_fail ("/");
+ setlocale_fail ("/../localedata/en_US.UTF-8");
+ setlocale_fail ("en_US.UTF-8/");
+ setlocale_fail ("en_US.UTF-8/..");
+ setlocale_fail ("en_US.UTF-8/../en_US.UTF-8");
+ setlocale_fail ("../localedata/en_US.UTF-8");
+ {
+ size_t large_length = 1024;
+ char *large_name = malloc (large_length + 1);
+ if (large_name == NULL)
+ {
+ puts ("malloc failure");
+ return 1;
+ }
+ memset (large_name, '/', large_length);
+ const char *suffix = "en_US.UTF-8";
+ strcpy (large_name + large_length - strlen (suffix), suffix);
+ setlocale_fail (large_name);
+ free (large_name);
+ }
+ {
+ size_t huge_length = 64 * 1024 * 1024;
+ char *huge_name = malloc (huge_length + 1);
+ if (huge_name == NULL)
+ {
+ puts ("malloc failure");
+ return 1;
+ }
+ memset (huge_name, 'X', huge_length);
+ huge_name[huge_length] = '\0';
+ /* Construct a composite locale specification. */
+ const char *prefix = "LC_CTYPE=de_DE.UTF-8;LC_TIME=";
+ memcpy (huge_name, prefix, strlen (prefix));
+ setlocale_fail (huge_name);
+ free (huge_name);
+ }
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
---
From d07eb371352d67ee4ef931b6956d1e0f28b599dc Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Wed, 28 May 2014 14:05:03 +0200
Subject: [PATCH] manual: Update the locale documentation
(cherry picked from commit 585367266923156ac6fb789939a923641ba5aaf4)
Conflicts:
manual/locale.texi
---
ChangeLog | 13 +++++
manual/locale.texi | 146 ++++++++++++++++++++++++++++++++++++++++-----------
2 files changed, 127 insertions(+), 32 deletions(-)
diff --git a/manual/locale.texi b/manual/locale.texi
index 8bfd653..ee1c3a1 100644
--- a/manual/locale.texi
+++ b/manual/locale.texi
@@ -29,6 +29,7 @@ will follow the conventions preferred by the user.
* Setting the Locale:: How a program specifies the locale
with library functions.
* Standard Locales:: Locale names available on all systems.
+* Locale Names:: Format of system-specific locale names.
* Locale Information:: How to access the information for the locale.
* Formatting Numbers:: A dedicated function to format numbers.
* Yes-or-No Questions:: Check a Response against the locale.
@@ -99,14 +100,16 @@ locale named @samp{espana-castellano} to use the standard conventions of
most of Spain.
The set of locales supported depends on the operating system you are
-using, and so do their names. We can't make any promises about what
-locales will exist, except for one standard locale called @samp{C} or
-@samp{POSIX}. Later we will describe how to construct locales.
-@comment (@pxref{Building Locale Files}).
+using, and so do their names, except that the standard locale called
+@samp{C} or @samp{POSIX} always exist. @xref{Locale Names}.
+
+In order to force the system to always use the default locale, the
+user can set the @code{LC_ALL} environment variable to @samp{C}.
@cindex combining locales
-A user also has the option of specifying different locales for different
-purposes---in effect, choosing a mixture of multiple locales.
+A user also has the option of specifying different locales for
+different purposes---in effect, choosing a mixture of multiple
+locales. @xref{Locale Categories}.
For example, the user might specify the locale @samp{espana-castellano}
for most purposes, but specify the locale @samp{usa-english} for
@@ -120,7 +123,7 @@ which locales apply. However, the user can choose to use each locale
for a particular subset of those purposes.
@node Locale Categories, Setting the Locale, Choosing Locale, Locales
-@section Categories of Activities that Locales Affect
+@section Locale Categories
@cindex categories for locales
@cindex locale categories
@@ -128,7 +131,11 @@ The purposes that locales serve are grouped into @dfn{categories}, so
that a user or a program can choose the locale for each category
independently. Here is a table of categories; each name is both an
environment variable that a user can set, and a macro name that you can
-use as an argument to @code{setlocale}.
+use as the first argument to @code{setlocale}.
+
+The contents of the environment variable (or the string in the second
+argument to @code{setlocale}) has to be a valid locale name.
+@xref{Locale Names}.
@vtable @code
@comment locale.h
@@ -172,7 +179,7 @@ for affirmative and negative responses.
@comment locale.h
@comment ISO
@item LC_ALL
-This is not an environment variable; it is only a macro that you can use
+This is not a category; it is only a macro that you can use
with @code{setlocale} to set a single locale for all purposes. Setting
this environment variable overwrites all selections by the other
@code{LC_*} variables or @code{LANG}.
@@ -355,13 +362,7 @@ The symbols in this section are defined in the header file @file{locale.h}.
@c strndup @ascuheap @acsmem
@c strcasecmp_l ok (C locale)
The function @code{setlocale} sets the current locale for category
-@var{category} to @var{locale}. A list of all the locales the system
-provides can be created by running
-
-@pindex locale
-@smallexample
- locale -a
-@end smallexample
+@var{category} to @var{locale}.
If @var{category} is @code{LC_ALL}, this specifies the locale for all
purposes. The other possible values of @var{category} specify an
@@ -386,10 +387,9 @@ is passed in as @var{locale} parameter.
When you read the current locale for category @code{LC_ALL}, the value
encodes the entire combination of selected locales for all categories.
-In this case, the value is not just a single locale name. In fact, we
-don't make any promises about what it looks like. But if you specify
-the same ``locale name'' with @code{LC_ALL} in a subsequent call to
-@code{setlocale}, it restores the same combination of locale selections.
+If you specify the same ``locale name'' with @code{LC_ALL} in a
+subsequent call to @code{setlocale}, it restores the same combination
+of locale selections.
To be sure you can use the returned string encoding the currently selected
locale at a later time, you must make a copy of the string. It is not
@@ -405,20 +405,15 @@ for @var{category}.
If a nonempty string is given for @var{locale}, then the locale of that
name is used if possible.
+The effective locale name (either the second argument to
+@code{setlocale}, or if the argument is an empty string, the name
+obtained from the process environment) must be valid locale name.
+@xref{Locale Names}.
+
If you specify an invalid locale name, @code{setlocale} returns a null
pointer and leaves the current locale unchanged.
@end deftypefun
-The path used for finding locale data can be set using the
-@code{LOCPATH} environment variable. The default path for finding
-locale data is system specific. It is computed from the value given
-as the prefix while configuring the C library. This value normally is
-@file{/usr} or @file{/}. For the former the complete path is:
-
-@smallexample
-/usr/lib/locale
-@end smallexample
-
Here is an example showing how you might use @code{setlocale} to
temporarily switch to a new locale.
@@ -458,7 +453,7 @@ locale categories, and future versions of the library will do so. For
portability, assume that any symbol beginning with @samp{LC_} might be
defined in @file{locale.h}.
-@node Standard Locales, Locale Information, Setting the Locale, Locales
+@node Standard Locales, Locale Names, Setting the Locale, Locales
@section Standard Locales
The only locale names you can count on finding on all operating systems
@@ -492,7 +487,94 @@ with the environment, rather than trying to specify some non-standard
locale explicitly by name. Remember, different machines might have
different sets of locales installed.
-@node Locale Information, Formatting Numbers, Standard Locales, Locales
+@node Locale Names, Locale Information, Standard Locales, Locales
+@section Locale Names
+
+The following command prints a list of locales supported by the
+system:
+
+@pindex locale
+@smallexample
+ locale -a
+@end smallexample
+
+@strong{Portability Note:} With the notable exception of the standard
+locale names @samp{C} and @samp{POSIX}, locale names are
+system-specific.
+
+Most locale names follow XPG syntax and consist of up to four parts:
+
+@smallexample
+@var{language}[_@var{territory}[.@var{codeset}]][@@@var{modifier}]
+@end smallexample
+
+Beside the first part, all of them are allowed to be missing. If the
+full specified locale is not found, less specific ones are looked for.
+The various parts will be stripped off, in the following order:
+
+@enumerate
+@item
+codeset
+@item
+normalized codeset
+@item
+territory
+@item
+modifier
+@end enumerate
+
+For example, the locale name @samp{de_AT.iso885915@@euro} denotes a
+German-language locale for use in Austria, using the ISO-8859-15
+(Latin-9) character set, and with the Euro as the currency symbol.
+
+In addition to locale names which follow XPG syntax, systems may
+provide aliases such as @samp{german}. Both categories of names must
+not contain the slash character @samp{/}.
+
+If the locale name starts with a slash @samp{/}, it is treated as a
+path relative to the configured locale directories; see @code{LOCPATH}
+below. The specified path must not contain a component @samp{..}, or
+the name is invalid, and @code{setlocale} will fail.
+
+@strong{Portability Note:} POSIX suggests that if a locale name starts
+with a slash @samp{/}, it is resolved as an absolute path. However,
+@theglibc{} treats it as a relative path under the directories listed
+in @code{LOCPATH} (or the default locale directory if @code{LOCPATH}
+is unset).
+
+Locale names which are longer than an implementation-defined limit are
+invalid and cause @code{setlocale} to fail.
+
+As a special case, locale names used with @code{LC_ALL} can combine
+several locales, reflecting different locale settings for different
+categories. For example, you might want to use a U.S. locale with ISO
+A4 paper format, so you set @code{LANG} to @samp{en_US.UTF-8}, and
+@code{LC_PAPER} to @samp{de_DE.UTF-8}. In this case, the
+@code{LC_ALL}-style combined locale name is
+
+@smallexample
+LC_CTYPE=en_US.UTF-8;LC_TIME=en_US.UTF-8;LC_PAPER=de_DE.UTF-8;@dots{}
+@end smallexample
+
+followed by other category settings not shown here.
+
+@vindex LOCPATH
+The path used for finding locale data can be set using the
+@code{LOCPATH} environment variable. This variable lists the
+directories in which to search for locale definitions, separated by a
+colon @samp{:}.
+
+The default path for finding locale data is system specific. A typical
+value for the @code{LOCPATH} default is:
+
+@smallexample
+/usr/share/locale
+@end smallexample
+
+The value of @code{LOCPATH} is ignored by privileged programs for
+security reasons, and only the default directory is used.
+
+@node Locale Information, Formatting Numbers, Locale Names, Locales
@section Accessing Locale Information
There are several ways to access locale information. The simplest
--
From b76db403426d4978ca2e60998c6dc62668a3f998 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Wed, 28 May 2014 14:41:52 +0200
Subject: [PATCH] setlocale: Use the heap for the copy of the locale argument
This avoids alloca calls with potentially large arguments.
(cherry picked from commit d183645616b0533b3acee28f1a95570bffbdf50f)
---
ChangeLog | 5 +++++
locale/setlocale.c | 14 ++++++++++++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/locale/setlocale.c b/locale/setlocale.c
index b70fa6c..a4c5983 100644
--- a/locale/setlocale.c
+++ b/locale/setlocale.c
@@ -272,6 +272,8 @@ setlocale (int category, const char *locale)
of entries of the form `CATEGORY=VALUE'. */
const char *newnames[__LC_LAST];
struct __locale_data *newdata[__LC_LAST];
+ /* Copy of the locale argument, for in-place splitting. */
+ char *locale_copy = NULL;
/* Set all name pointers to the argument name. */
for (category = 0; category < __LC_LAST; ++category)
@@ -281,7 +283,13 @@ setlocale (int category, const char *locale)
if (__builtin_expect (strchr (locale, ';') != NULL, 0))
{
/* This is a composite name. Make a copy and split it up. */
- char *np = strdupa (locale);
+ locale_copy = strdup (locale);
+ if (__glibc_unlikely (locale_copy == NULL))
+ {
+ __libc_rwlock_unlock (__libc_setlocale_lock);
+ return NULL;
+ }
+ char *np = locale_copy;
char *cp;
int cnt;
@@ -299,6 +307,7 @@ setlocale (int category, const char *locale)
{
error_return:
__libc_rwlock_unlock (__libc_setlocale_lock);
+ free (locale_copy);
/* Bogus category name. */
ERROR_RETURN;
@@ -391,8 +400,9 @@ setlocale (int category, const char *locale)
/* Critical section left. */
__libc_rwlock_unlock (__libc_setlocale_lock);
- /* Free the resources (the locale path variable). */
+ /* Free the resources. */
free (locale_path);
+ free (locale_copy);
return composite;
}
--
1.7.1
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