glibc : Fix CVE-2021-3998

Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=062ff490c1467059f6cd64bb9c3d85f6cc6cf97a]
Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5]

(From OE-Core rev: 20cc83dd8d323d7ea86b3625f4e8da94c160def9)

Signed-off-by: pgowda <pgowda.cve@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Pgowda
2022-01-24 05:10:42 -08:00
committed by Richard Purdie
parent 21e5b78d9a
commit 359fcb9ed2
3 changed files with 422 additions and 0 deletions

View File

@@ -0,0 +1,282 @@
From fb7bff12e81c677a6622f724edd4d4987dd9d971 Mon Sep 17 00:00:00 2001
From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Tue, 18 Jan 2022 13:29:36 +0530
Subject: [PATCH] support: Add helpers to create paths longer than PATH_MAX
Add new helpers support_create_and_chdir_toolong_temp_directory and
support_chdir_toolong_temp_directory to create and descend into
directory trees longer than PATH_MAX.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=062ff490c1467059f6cd64bb9c3d85f6cc6cf97a]
CVE: CVE-2021-3998
Signed-off-by: Pgowda <pgowda.cve@gmail.com>
---
support/temp_file.c | 159 +++++++++++++++++++++++++++++++++++++++++---
support/temp_file.h | 9 +++
2 files changed, 159 insertions(+), 9 deletions(-)
diff --git a/support/temp_file.c b/support/temp_file.c
index e7bb8aadb9..e41128c2d4 100644
--- a/support/temp_file.c
+++ b/support/temp_file.c
@@ -1,5 +1,6 @@
/* Temporary file handling for tests.
Copyright (C) 1998-2021 Free Software Foundation, Inc.
+ Copyright The GNU Tools Authors.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -20,15 +21,17 @@
some 32-bit platforms. */
#define _FILE_OFFSET_BITS 64
+#include <support/check.h>
#include <support/temp_file.h>
#include <support/temp_file-internal.h>
#include <support/support.h>
+#include <errno.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <unistd.h>
+#include <xunistd.h>
/* List of temporary files. */
static struct temp_name_list
@@ -36,14 +39,20 @@ static struct temp_name_list
struct temp_name_list *next;
char *name;
pid_t owner;
+ bool toolong;
} *temp_name_list;
/* Location of the temporary files. Set by the test skeleton via
support_set_test_dir. The string is not be freed. */
static const char *test_dir = _PATH_TMP;
-void
-add_temp_file (const char *name)
+/* Name of subdirectories in a too long temporary directory tree. */
+static char toolong_subdir[NAME_MAX + 1];
+static bool toolong_initialized;
+static size_t toolong_path_max;
+
+static void
+add_temp_file_internal (const char *name, bool toolong)
{
struct temp_name_list *newp
= (struct temp_name_list *) xcalloc (sizeof (*newp), 1);
@@ -53,12 +62,19 @@ add_temp_file (const char *name)
newp->name = newname;
newp->next = temp_name_list;
newp->owner = getpid ();
+ newp->toolong = toolong;
temp_name_list = newp;
}
else
free (newp);
}
+void
+add_temp_file (const char *name)
+{
+ add_temp_file_internal (name, false);
+}
+
int
create_temp_file_in_dir (const char *base, const char *dir, char **filename)
{
@@ -90,8 +106,8 @@ create_temp_file (const char *base, char
return create_temp_file_in_dir (base, test_dir, filename);
}
-char *
-support_create_temp_directory (const char *base)
+static char *
+create_temp_directory_internal (const char *base, bool toolong)
{
char *path = xasprintf ("%s/%sXXXXXX", test_dir, base);
if (mkdtemp (path) == NULL)
@@ -99,16 +115,132 @@ support_create_temp_directory (const cha
printf ("error: mkdtemp (\"%s\"): %m", path);
exit (1);
}
- add_temp_file (path);
+ add_temp_file_internal (path, toolong);
return path;
}
-/* Helper functions called by the test skeleton follow. */
+char *
+support_create_temp_directory (const char *base)
+{
+ return create_temp_directory_internal (base, false);
+}
+
+static void
+ensure_toolong_initialized (void)
+{
+ if (!toolong_initialized)
+ FAIL_EXIT1 ("uninitialized toolong directory tree\n");
+}
+
+static void
+initialize_toolong (const char *base)
+{
+ long name_max = pathconf (base, _PC_NAME_MAX);
+ name_max = (name_max < 0 ? 64
+ : (name_max < sizeof (toolong_subdir) ? name_max
+ : sizeof (toolong_subdir) - 1));
+
+ long path_max = pathconf (base, _PC_PATH_MAX);
+ path_max = (path_max < 0 ? 1024
+ : path_max <= PTRDIFF_MAX ? path_max : PTRDIFF_MAX);
+
+ /* Sanity check to ensure that the test does not create temporary directories
+ in different filesystems because this API doesn't support it. */
+ if (toolong_initialized)
+ {
+ if (name_max != strlen (toolong_subdir))
+ FAIL_UNSUPPORTED ("name_max: Temporary directories in different"
+ " filesystems not supported yet\n");
+ if (path_max != toolong_path_max)
+ FAIL_UNSUPPORTED ("path_max: Temporary directories in different"
+ " filesystems not supported yet\n");
+ return;
+ }
+
+ toolong_path_max = path_max;
+
+ size_t len = name_max;
+ memset (toolong_subdir, 'X', len);
+ toolong_initialized = true;
+}
+
+char *
+support_create_and_chdir_toolong_temp_directory (const char *basename)
+{
+ char *base = create_temp_directory_internal (basename, true);
+ xchdir (base);
+
+ initialize_toolong (base);
+
+ size_t sz = strlen (toolong_subdir);
+
+ /* Create directories and descend into them so that the final path is larger
+ than PATH_MAX. */
+ for (size_t i = 0; i <= toolong_path_max / sz; i++)
+ {
+ int ret = mkdir (toolong_subdir, S_IRWXU);
+ if (ret != 0 && errno == ENAMETOOLONG)
+ FAIL_UNSUPPORTED ("Filesystem does not support creating too long "
+ "directory trees\n");
+ else if (ret != 0)
+ FAIL_EXIT1 ("Failed to create directory tree: %m\n");
+ xchdir (toolong_subdir);
+ }
+ return base;
+}
void
-support_set_test_dir (const char *path)
+support_chdir_toolong_temp_directory (const char *base)
{
- test_dir = path;
+ ensure_toolong_initialized ();
+
+ xchdir (base);
+
+ size_t sz = strlen (toolong_subdir);
+ for (size_t i = 0; i <= toolong_path_max / sz; i++)
+ xchdir (toolong_subdir);
+}
+
+/* Helper functions called by the test skeleton follow. */
+
+static void
+remove_toolong_subdirs (const char *base)
+{
+ ensure_toolong_initialized ();
+
+ if (chdir (base) != 0)
+ {
+ printf ("warning: toolong cleanup base failed: chdir (\"%s\"): %m\n",
+ base);
+ return;
+ }
+
+ /* Descend. */
+ int levels = 0;
+ size_t sz = strlen (toolong_subdir);
+ for (levels = 0; levels <= toolong_path_max / sz; levels++)
+ if (chdir (toolong_subdir) != 0)
+ {
+ printf ("warning: toolong cleanup failed: chdir (\"%s\"): %m\n",
+ toolong_subdir);
+ break;
+ }
+
+ /* Ascend and remove. */
+ while (--levels >= 0)
+ {
+ if (chdir ("..") != 0)
+ {
+ printf ("warning: toolong cleanup failed: chdir (\"..\"): %m\n");
+ return;
+ }
+ if (remove (toolong_subdir) != 0)
+ {
+ printf ("warning: could not remove subdirectory: %s: %m\n",
+ toolong_subdir);
+ return;
+ }
+ }
}
void
@@ -123,6 +255,9 @@ support_delete_temp_files (void)
around, to prevent PID reuse.) */
if (temp_name_list->owner == pid)
{
+ if (temp_name_list->toolong)
+ remove_toolong_subdirs (temp_name_list->name);
+
if (remove (temp_name_list->name) != 0)
printf ("warning: could not remove temporary file: %s: %m\n",
temp_name_list->name);
@@ -147,3 +282,9 @@ support_print_temp_files (FILE *f)
fprintf (f, ")\n");
}
}
+
+void
+support_set_test_dir (const char *path)
+{
+ test_dir = path;
+}
diff --git a/support/temp_file.h b/support/temp_file.h
index 50a443abe4..8459ddda72 100644
--- a/support/temp_file.h
+++ b/support/temp_file.h
@@ -44,6 +44,15 @@ int create_temp_file_in_dir (const char
returns. The caller should free this string. */
char *support_create_temp_directory (const char *base);
+/* Create a temporary directory tree that is longer than PATH_MAX and schedule
+ it for deletion. BASENAME is used as a prefix for the unique directory
+ name, which the function returns. The caller should free this string. */
+char *support_create_and_chdir_toolong_temp_directory (const char *basename);
+
+/* Change into the innermost directory of the directory tree BASE, which was
+ created using support_create_and_chdir_toolong_temp_directory. */
+void support_chdir_toolong_temp_directory (const char *base);
+
__END_DECLS
#endif /* SUPPORT_TEMP_FILE_H */

View File

@@ -0,0 +1,138 @@
From f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5 Mon Sep 17 00:00:00 2001
From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Thu, 13 Jan 2022 11:28:36 +0530
Subject: [PATCH] realpath: Set errno to ENAMETOOLONG for result larger than
PATH_MAX [BZ #28770]
realpath returns an allocated string when the result exceeds PATH_MAX,
which is unexpected when its second argument is not NULL. This results
in the second argument (resolved) being uninitialized and also results
in a memory leak since the caller expects resolved to be the same as the
returned value.
Return NULL and set errno to ENAMETOOLONG if the result exceeds
PATH_MAX. This fixes [BZ #28770], which is CVE-2021-3998.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit ee8d5e33adb284601c00c94687bc907e10aec9bb)
Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5]
CVE: CVE-2021-3998
Signed-off-by: Pgowda <pgowda.cve@gmail.com>
---
NEWS | 4 +++
stdlib/Makefile | 1 +
stdlib/canonicalize.c | 12 +++++++--
stdlib/tst-realpath-toolong.c | 49 +++++++++++++++++++++++++++++++++++
4 files changed, 64 insertions(+), 2 deletions(-)
create mode 100644 stdlib/tst-realpath-toolong.c
diff --git a/NEWS b/NEWS
index 7e773bd005..b4f81c2668 100644
--- a/NEWS
+++ b/NEWS
@@ -210,6 +210,10 @@ Security related changes:
legacy function could result in a stack-based buffer overflow when
using the "unix" protocol. Reported by Martin Sebor.
+ CVE-2021-3998: Passing a path longer than PATH_MAX to the realpath
+ function could result in a memory leak and potential access of
+ uninitialized memory. Reported by Qualys.
+
The following bugs are resolved with this release:
[4737] libc: fork is not async-signal-safe
diff --git a/stdlib/canonicalize.c b/stdlib/canonicalize.c
index 698f9ede25..7a23a51b3a 100644
--- a/stdlib/canonicalize.c
+++ b/stdlib/canonicalize.c
@@ -400,8 +400,16 @@ realpath_stk (const char *name, char *re
error:
*dest++ = '\0';
- if (resolved != NULL && dest - rname <= get_path_max ())
- rname = strcpy (resolved, rname);
+ if (resolved != NULL)
+ {
+ if (dest - rname <= get_path_max ())
+ rname = strcpy (resolved, rname);
+ else
+ {
+ failed = true;
+ __set_errno (ENAMETOOLONG);
+ }
+ }
error_nomem:
scratch_buffer_free (&extra_buffer);
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 9bb5c221e8..a4ac30d1f6 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -88,7 +88,8 @@ tests := tst-strtol tst-strtod testmb t
tst-swapcontext1 tst-setcontext4 tst-setcontext5 \
tst-setcontext6 tst-setcontext7 tst-setcontext8 \
tst-setcontext9 tst-bz20544 tst-canon-bz26341 \
- tst-realpath
+ tst-realpath \
+ tst-realpath-toolong
tests-internal := tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \
tst-tls-atexit tst-tls-atexit-nodelete
diff --git a/stdlib/tst-realpath-toolong.c b/stdlib/tst-realpath-toolong.c
new file mode 100644
index 0000000000..8bed772460
--- /dev/null
+++ b/stdlib/tst-realpath-toolong.c
@@ -0,0 +1,49 @@
+/* Verify that realpath returns NULL with ENAMETOOLONG if the result exceeds
+ NAME_MAX.
+ Copyright The GNU Toolchain Authors.
+ 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#define BASENAME "tst-realpath-toolong."
+
+int
+do_test (void)
+{
+ char *base = support_create_and_chdir_toolong_temp_directory (BASENAME);
+
+ char buf[PATH_MAX + 1];
+ const char *res = realpath (".", buf);
+
+ /* canonicalize.c states that if the real path is >= PATH_MAX, then
+ realpath returns NULL and sets ENAMETOOLONG. */
+ TEST_VERIFY (res == NULL);
+ TEST_VERIFY (errno == ENAMETOOLONG);
+
+ free (base);
+ return 0;
+}
+
+#include <support/test-driver.c>

View File

@@ -57,6 +57,8 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
file://0002-CVE-2022-23218.patch \
file://0001-CVE-2022-23219.patch \
file://0002-CVE-2022-23219.patch \
file://0001-CVE-2021-3998.patch \
file://0002-CVE-2021-3998.patch \
"
S = "${WORKDIR}/git"
B = "${WORKDIR}/build-${TARGET_SYS}"