* [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999
@ 2022-01-24 6:50 Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 1/6] support: Add helpers to create paths longer than PATH_MAX Siddhesh Poyarekar
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable
Backported to 2.34 branch.
Siddhesh Poyarekar (6):
support: Add helpers to create paths longer than PATH_MAX
stdlib: Sort tests in Makefile
stdlib: Fix formatting of tests list in Makefile
realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX
[BZ #28770]
tst-realpath-toolong: Fix hurd build
getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999)
NEWS | 10 +
stdlib/Makefile | 102 ++++++--
stdlib/canonicalize.c | 12 +-
stdlib/tst-realpath-toolong.c | 53 ++++
support/temp_file.c | 161 +++++++++++-
support/temp_file.h | 9 +
sysdeps/posix/getcwd.c | 7 +
sysdeps/unix/sysv/linux/Makefile | 7 +-
.../unix/sysv/linux/tst-getcwd-smallbuff.c | 241 ++++++++++++++++++
9 files changed, 565 insertions(+), 37 deletions(-)
create mode 100644 stdlib/tst-realpath-toolong.c
create mode 100644 sysdeps/unix/sysv/linux/tst-getcwd-smallbuff.c
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 1/6] support: Add helpers to create paths longer than PATH_MAX
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 2/6] stdlib: Sort tests in Makefile Siddhesh Poyarekar
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable
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>
(cherry picked from commit fb7bff12e81c677a6622f724edd4d4987dd9d971)
---
support/temp_file.c | 161 +++++++++++++++++++++++++++++++++++++++++---
support/temp_file.h | 9 +++
2 files changed, 160 insertions(+), 10 deletions(-)
diff --git a/support/temp_file.c b/support/temp_file.c
index c6df641876..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 (C) 1998-2022 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 **filename)
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 char *base)
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 f3a7fb6f9c..a22964c6fa 100644
--- a/support/temp_file.h
+++ b/support/temp_file.h
@@ -44,6 +44,15 @@ int create_temp_file_in_dir (const char *base, const char *dir,
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 */
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 2/6] stdlib: Sort tests in Makefile
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 1/6] support: Add helpers to create paths longer than PATH_MAX Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 3/6] stdlib: Fix formatting of tests list " Siddhesh Poyarekar
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable
Put one test per line and sort them.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 5b766603efa727c236a5f0cdcf09b71ff60b7584)
---
stdlib/Makefile | 99 +++++++++++++++++++++++++++++++++++++------------
1 file changed, 75 insertions(+), 24 deletions(-)
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 7c15549caf..6a1c3580bd 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -65,30 +65,81 @@ aux = grouping groupingwc tens_in_limb
static-only-routines = atexit at_quick_exit
test-srcs := tst-fmtmsg
-tests := tst-strtol tst-strtod testmb testrand testsort testdiv \
- test-canon test-canon2 tst-strtoll tst-environ \
- tst-xpg-basename tst-random tst-random2 tst-bsearch \
- tst-limits tst-rand48 bug-strtod tst-setcontext \
- tst-setcontext2 test-a64l tst-qsort testmb2 \
- bug-strtod2 tst-atof1 tst-atof2 tst-strtod2 \
- tst-rand48-2 tst-makecontext tst-strtod5 \
- tst-qsort2 tst-makecontext2 tst-strtod6 tst-unsetenv1 \
- tst-makecontext3 bug-getcontext bug-fmtmsg1 \
- tst-secure-getenv tst-strtod-overflow tst-strtod-round \
- tst-tininess tst-strtod-underflow tst-setcontext3 \
- tst-strtol-locale tst-strtod-nan-locale tst-strfmon_l \
- tst-quick_exit tst-thread-quick_exit tst-width \
- tst-width-stdint tst-strfrom tst-strfrom-locale \
- tst-getrandom tst-atexit tst-at_quick_exit \
- tst-cxa_atexit tst-on_exit test-atexit-race \
- test-at_quick_exit-race test-cxa_atexit-race \
- test-cxa_atexit-race2 \
- test-on_exit-race test-dlclose-exit-race \
- tst-makecontext-align test-bz22786 tst-strtod-nan-sign \
- tst-swapcontext1 tst-setcontext4 tst-setcontext5 \
- tst-setcontext6 tst-setcontext7 tst-setcontext8 \
- tst-setcontext9 tst-bz20544 tst-canon-bz26341 \
- tst-realpath
+tests := bug-fmtmsg1 \
+ bug-getcontext \
+ bug-strtod \
+ bug-strtod2 \
+ test-a64l \
+ test-at_quick_exit-race \
+ test-atexit-race \
+ test-bz22786 \
+ test-canon \
+ test-canon2 \
+ test-cxa_atexit-race \
+ test-cxa_atexit-race2 \
+ test-dlclose-exit-race \
+ test-on_exit-race \
+ testdiv \
+ testmb \
+ testmb2 \
+ testrand \
+ testsort \
+ tst-at_quick_exit \
+ tst-atexit \
+ tst-atof1 \
+ tst-atof2 \
+ tst-bsearch \
+ tst-bz20544 \
+ tst-canon-bz26341 \
+ tst-cxa_atexit \
+ tst-environ \
+ tst-getrandom \
+ tst-limits \
+ tst-makecontext \
+ tst-makecontext-align \
+ tst-makecontext2 \
+ tst-makecontext3 \
+ tst-on_exit \
+ tst-qsort \
+ tst-qsort2 \
+ tst-quick_exit \
+ tst-rand48 \
+ tst-rand48-2 \
+ tst-random \
+ tst-random2 \
+ tst-realpath \
+ tst-secure-getenv \
+ tst-setcontext \
+ tst-setcontext2 \
+ tst-setcontext3 \
+ tst-setcontext4 \
+ tst-setcontext5 \
+ tst-setcontext6 \
+ tst-setcontext7 \
+ tst-setcontext8 \
+ tst-setcontext9 \
+ tst-strfmon_l \
+ tst-strfrom \
+ tst-strfrom-locale \
+ tst-strtod \
+ tst-strtod-nan-locale \
+ tst-strtod-nan-sign \
+ tst-strtod-overflow \
+ tst-strtod-round \
+ tst-strtod-underflow \
+ tst-strtod2 \
+ tst-strtod5 \
+ tst-strtod6 \
+ tst-strtol \
+ tst-strtol-locale \
+ tst-strtoll \
+ tst-swapcontext1 \
+ tst-thread-quick_exit \
+ tst-tininess \
+ tst-unsetenv1 \
+ tst-width \
+ tst-width-stdint \
+ tst-xpg-basename
tests-internal := tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \
tst-tls-atexit tst-tls-atexit-nodelete
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 3/6] stdlib: Fix formatting of tests list in Makefile
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 1/6] support: Add helpers to create paths longer than PATH_MAX Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 2/6] stdlib: Sort tests in Makefile Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 4/6] realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770] Siddhesh Poyarekar
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable; +Cc: Florian Weimer
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit f9dab1b5f23d0fb008a56c7c6c8919adb49d3611)
---
stdlib/Makefile | 152 ++++++++++++++++++++++++------------------------
1 file changed, 77 insertions(+), 75 deletions(-)
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 6a1c3580bd..9bb5c221e8 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -65,81 +65,83 @@ aux = grouping groupingwc tens_in_limb
static-only-routines = atexit at_quick_exit
test-srcs := tst-fmtmsg
-tests := bug-fmtmsg1 \
- bug-getcontext \
- bug-strtod \
- bug-strtod2 \
- test-a64l \
- test-at_quick_exit-race \
- test-atexit-race \
- test-bz22786 \
- test-canon \
- test-canon2 \
- test-cxa_atexit-race \
- test-cxa_atexit-race2 \
- test-dlclose-exit-race \
- test-on_exit-race \
- testdiv \
- testmb \
- testmb2 \
- testrand \
- testsort \
- tst-at_quick_exit \
- tst-atexit \
- tst-atof1 \
- tst-atof2 \
- tst-bsearch \
- tst-bz20544 \
- tst-canon-bz26341 \
- tst-cxa_atexit \
- tst-environ \
- tst-getrandom \
- tst-limits \
- tst-makecontext \
- tst-makecontext-align \
- tst-makecontext2 \
- tst-makecontext3 \
- tst-on_exit \
- tst-qsort \
- tst-qsort2 \
- tst-quick_exit \
- tst-rand48 \
- tst-rand48-2 \
- tst-random \
- tst-random2 \
- tst-realpath \
- tst-secure-getenv \
- tst-setcontext \
- tst-setcontext2 \
- tst-setcontext3 \
- tst-setcontext4 \
- tst-setcontext5 \
- tst-setcontext6 \
- tst-setcontext7 \
- tst-setcontext8 \
- tst-setcontext9 \
- tst-strfmon_l \
- tst-strfrom \
- tst-strfrom-locale \
- tst-strtod \
- tst-strtod-nan-locale \
- tst-strtod-nan-sign \
- tst-strtod-overflow \
- tst-strtod-round \
- tst-strtod-underflow \
- tst-strtod2 \
- tst-strtod5 \
- tst-strtod6 \
- tst-strtol \
- tst-strtol-locale \
- tst-strtoll \
- tst-swapcontext1 \
- tst-thread-quick_exit \
- tst-tininess \
- tst-unsetenv1 \
- tst-width \
- tst-width-stdint \
- tst-xpg-basename
+tests := \
+ bug-fmtmsg1 \
+ bug-getcontext \
+ bug-strtod \
+ bug-strtod2 \
+ test-a64l \
+ test-at_quick_exit-race \
+ test-atexit-race \
+ test-bz22786 \
+ test-canon \
+ test-canon2 \
+ test-cxa_atexit-race \
+ test-cxa_atexit-race2 \
+ test-dlclose-exit-race \
+ test-on_exit-race \
+ testdiv \
+ testmb \
+ testmb2 \
+ testrand \
+ testsort \
+ tst-at_quick_exit \
+ tst-atexit \
+ tst-atof1 \
+ tst-atof2 \
+ tst-bsearch \
+ tst-bz20544 \
+ tst-canon-bz26341 \
+ tst-cxa_atexit \
+ tst-environ \
+ tst-getrandom \
+ tst-limits \
+ tst-makecontext \
+ tst-makecontext-align \
+ tst-makecontext2 \
+ tst-makecontext3 \
+ tst-on_exit \
+ tst-qsort \
+ tst-qsort2 \
+ tst-quick_exit \
+ tst-rand48 \
+ tst-rand48-2 \
+ tst-random \
+ tst-random2 \
+ tst-realpath \
+ tst-secure-getenv \
+ tst-setcontext \
+ tst-setcontext2 \
+ tst-setcontext3 \
+ tst-setcontext4 \
+ tst-setcontext5 \
+ tst-setcontext6 \
+ tst-setcontext7 \
+ tst-setcontext8 \
+ tst-setcontext9 \
+ tst-strfmon_l \
+ tst-strfrom \
+ tst-strfrom-locale \
+ tst-strtod \
+ tst-strtod-nan-locale \
+ tst-strtod-nan-sign \
+ tst-strtod-overflow \
+ tst-strtod-round \
+ tst-strtod-underflow \
+ tst-strtod2 \
+ tst-strtod5 \
+ tst-strtod6 \
+ tst-strtol \
+ tst-strtol-locale \
+ tst-strtoll \
+ tst-swapcontext1 \
+ tst-thread-quick_exit \
+ tst-tininess \
+ tst-unsetenv1 \
+ tst-width \
+ tst-width-stdint \
+ tst-xpg-basename \
+# tests
tests-internal := tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \
tst-tls-atexit tst-tls-atexit-nodelete
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 4/6] realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770]
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
` (2 preceding siblings ...)
2022-01-24 6:50 ` [committed 2.34 3/6] stdlib: Fix formatting of tests list " Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 5/6] tst-realpath-toolong: Fix hurd build Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 6/6] getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999) Siddhesh Poyarekar
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable
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)
---
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
@@ -16,6 +16,10 @@ Security related changes:
CVE-2022-23218: Passing an overlong file name to the svcunix_create
legacy function could result in a stack-based buffer overflow.
+ 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:
[12889] nptl: Fix race between pthread_kill and thread exit
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 9bb5c221e8..a4ac30d1f6 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -109,6 +109,7 @@ tests := \
tst-random \
tst-random2 \
tst-realpath \
+ tst-realpath-toolong \
tst-secure-getenv \
tst-setcontext \
tst-setcontext2 \
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 *resolved,
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/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>
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 5/6] tst-realpath-toolong: Fix hurd build
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
` (3 preceding siblings ...)
2022-01-24 6:50 ` [committed 2.34 4/6] realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770] Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 6/6] getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999) Siddhesh Poyarekar
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable
Define PATH_MAX to a constant if it isn't already defined, like in hurd.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 976db046bc3a3738f69255ae00b0a09b8e77fd9c)
---
stdlib/tst-realpath-toolong.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/stdlib/tst-realpath-toolong.c b/stdlib/tst-realpath-toolong.c
index 8bed772460..4388890294 100644
--- a/stdlib/tst-realpath-toolong.c
+++ b/stdlib/tst-realpath-toolong.c
@@ -29,6 +29,10 @@
#define BASENAME "tst-realpath-toolong."
+#ifndef PATH_MAX
+# define PATH_MAX 1024
+#endif
+
int
do_test (void)
{
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [committed 2.34 6/6] getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999)
2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
` (4 preceding siblings ...)
2022-01-24 6:50 ` [committed 2.34 5/6] tst-realpath-toolong: Fix hurd build Siddhesh Poyarekar
@ 2022-01-24 6:50 ` Siddhesh Poyarekar
5 siblings, 0 replies; 7+ messages in thread
From: Siddhesh Poyarekar @ 2022-01-24 6:50 UTC (permalink / raw)
To: libc-stable; +Cc: Andreas Schwab, Adhemerval Zanella, Qualys Security Advisory
No valid path returned by getcwd would fit into 1 byte, so reject the
size early and return NULL with errno set to ERANGE. This change is
prompted by CVE-2021-3999, which describes a single byte buffer
underflow and overflow when all of the following conditions are met:
- The buffer size (i.e. the second argument of getcwd) is 1 byte
- The current working directory is too long
- '/' is also mounted on the current working directory
Sequence of events:
- In sysdeps/unix/sysv/linux/getcwd.c, the syscall returns ENAMETOOLONG
because the linux kernel checks for name length before it checks
buffer size
- The code falls back to the generic getcwd in sysdeps/posix
- In the generic func, the buf[0] is set to '\0' on line 250
- this while loop on line 262 is bypassed:
while (!(thisdev == rootdev && thisino == rootino))
since the rootfs (/) is bind mounted onto the directory and the flow
goes on to line 449, where it puts a '/' in the byte before the
buffer.
- Finally on line 458, it moves 2 bytes (the underflowed byte and the
'\0') to the buf[0] and buf[1], resulting in a 1 byte buffer overflow.
- buf is returned on line 469 and errno is not set.
This resolves BZ #28769.
Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Qualys Security Advisory <qsa@qualys.com>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 23e0e8f5f1fb5ed150253d986ecccdc90c2dcd5e)
---
NEWS | 6 +
sysdeps/posix/getcwd.c | 7 +
sysdeps/unix/sysv/linux/Makefile | 7 +-
.../unix/sysv/linux/tst-getcwd-smallbuff.c | 241 ++++++++++++++++++
4 files changed, 260 insertions(+), 1 deletion(-)
create mode 100644 sysdeps/unix/sysv/linux/tst-getcwd-smallbuff.c
diff --git a/NEWS b/NEWS
index b4f81c2668..8d7467d2c1 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,12 @@ Security related changes:
function could result in a memory leak and potential access of
uninitialized memory. Reported by Qualys.
+ CVE-2021-3999: Passing a buffer of size exactly 1 byte to the getcwd
+ function may result in an off-by-one buffer underflow and overflow
+ when the current working directory is longer than PATH_MAX and also
+ corresponds to the / directory through an unprivileged mount
+ namespace. Reported by Qualys.
+
The following bugs are resolved with this release:
[12889] nptl: Fix race between pthread_kill and thread exit
diff --git a/sysdeps/posix/getcwd.c b/sysdeps/posix/getcwd.c
index 13680026ff..b6984a382c 100644
--- a/sysdeps/posix/getcwd.c
+++ b/sysdeps/posix/getcwd.c
@@ -187,6 +187,13 @@ __getcwd_generic (char *buf, size_t size)
size_t allocated = size;
size_t used;
+ /* A size of 1 byte is never useful. */
+ if (allocated == 1)
+ {
+ __set_errno (ERANGE);
+ return NULL;
+ }
+
#if HAVE_MINIMALLY_WORKING_GETCWD
/* If AT_FDCWD is not defined, the algorithm below is O(N**2) and
this is much slower than the system getcwd (at least on
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 76ad06361c..9380d3848d 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -331,7 +331,12 @@ sysdep_routines += xstatconv internal_statvfs \
sysdep_headers += bits/fcntl-linux.h
-tests += tst-fallocate tst-fallocate64 tst-o_path-locks
+tests += \
+ tst-fallocate \
+ tst-fallocate64 \
+ tst-getcwd-smallbuff \
+ tst-o_path-locks \
+# tests
endif
ifeq ($(subdir),elf)
diff --git a/sysdeps/unix/sysv/linux/tst-getcwd-smallbuff.c b/sysdeps/unix/sysv/linux/tst-getcwd-smallbuff.c
new file mode 100644
index 0000000000..d460d6e766
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-getcwd-smallbuff.c
@@ -0,0 +1,241 @@
+/* Verify that getcwd returns ERANGE for size 1 byte and does not underflow
+ buffer when the CWD is too long and is also a mount target of /. See bug
+ #28769 or CVE-2021-3999 for more context.
+ 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 <fcntl.h>
+#include <intprops.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/xsched.h>
+#include <support/xunistd.h>
+
+static char *base;
+#define BASENAME "tst-getcwd-smallbuff"
+#define MOUNT_NAME "mpoint"
+static int sockfd[2];
+
+static void
+do_cleanup (void)
+{
+ support_chdir_toolong_temp_directory (base);
+ TEST_VERIFY_EXIT (rmdir (MOUNT_NAME) == 0);
+ free (base);
+}
+
+static void
+send_fd (const int sock, const int fd)
+{
+ struct msghdr msg = {0};
+ union
+ {
+ struct cmsghdr hdr;
+ char buf[CMSG_SPACE (sizeof (int))];
+ } cmsgbuf = {0};
+ struct cmsghdr *cmsg;
+ struct iovec vec;
+ char ch = 'A';
+ ssize_t n;
+
+ msg.msg_control = &cmsgbuf.buf;
+ msg.msg_controllen = sizeof (cmsgbuf.buf);
+
+ cmsg = CMSG_FIRSTHDR (&msg);
+ cmsg->cmsg_len = CMSG_LEN (sizeof (int));
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+ memcpy (CMSG_DATA (cmsg), &fd, sizeof (fd));
+
+ vec.iov_base = &ch;
+ vec.iov_len = 1;
+ msg.msg_iov = &vec;
+ msg.msg_iovlen = 1;
+
+ while ((n = sendmsg (sock, &msg, 0)) == -1 && errno == EINTR);
+
+ TEST_VERIFY_EXIT (n == 1);
+}
+
+static int
+recv_fd (const int sock)
+{
+ struct msghdr msg = {0};
+ union
+ {
+ struct cmsghdr hdr;
+ char buf[CMSG_SPACE(sizeof(int))];
+ } cmsgbuf = {0};
+ struct cmsghdr *cmsg;
+ struct iovec vec;
+ ssize_t n;
+ char ch = '\0';
+ int fd = -1;
+
+ vec.iov_base = &ch;
+ vec.iov_len = 1;
+ msg.msg_iov = &vec;
+ msg.msg_iovlen = 1;
+
+ msg.msg_control = &cmsgbuf.buf;
+ msg.msg_controllen = sizeof (cmsgbuf.buf);
+
+ while ((n = recvmsg (sock, &msg, 0)) == -1 && errno == EINTR);
+ if (n != 1 || ch != 'A')
+ return -1;
+
+ cmsg = CMSG_FIRSTHDR (&msg);
+ if (cmsg == NULL)
+ return -1;
+ if (cmsg->cmsg_type != SCM_RIGHTS)
+ return -1;
+ memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd));
+ if (fd < 0)
+ return -1;
+ return fd;
+}
+
+static int
+child_func (void * const arg)
+{
+ xclose (sockfd[0]);
+ const int sock = sockfd[1];
+ char ch;
+
+ TEST_VERIFY_EXIT (read (sock, &ch, 1) == 1);
+ TEST_VERIFY_EXIT (ch == '1');
+
+ if (mount ("/", MOUNT_NAME, NULL, MS_BIND | MS_REC, NULL))
+ FAIL_EXIT1 ("mount failed: %m\n");
+ const int fd = xopen ("mpoint",
+ O_RDONLY | O_PATH | O_DIRECTORY | O_NOFOLLOW, 0);
+
+ send_fd (sock, fd);
+ xclose (fd);
+
+ TEST_VERIFY_EXIT (read (sock, &ch, 1) == 1);
+ TEST_VERIFY_EXIT (ch == 'a');
+
+ xclose (sock);
+ return 0;
+}
+
+static void
+update_map (char * const mapping, const char * const map_file)
+{
+ const size_t map_len = strlen (mapping);
+
+ const int fd = xopen (map_file, O_WRONLY, 0);
+ xwrite (fd, mapping, map_len);
+ xclose (fd);
+}
+
+static void
+proc_setgroups_write (const long child_pid, const char * const str)
+{
+ const size_t str_len = strlen(str);
+
+ char setgroups_path[sizeof ("/proc//setgroups") + INT_STRLEN_BOUND (long)];
+
+ snprintf (setgroups_path, sizeof (setgroups_path),
+ "/proc/%ld/setgroups", child_pid);
+
+ const int fd = open (setgroups_path, O_WRONLY);
+
+ if (fd < 0)
+ {
+ TEST_VERIFY_EXIT (errno == ENOENT);
+ FAIL_UNSUPPORTED ("/proc/%ld/setgroups not found\n", child_pid);
+ }
+
+ xwrite (fd, str, str_len);
+ xclose(fd);
+}
+
+static char child_stack[1024 * 1024];
+
+int
+do_test (void)
+{
+ base = support_create_and_chdir_toolong_temp_directory (BASENAME);
+
+ xmkdir (MOUNT_NAME, S_IRWXU);
+ atexit (do_cleanup);
+
+ TEST_VERIFY_EXIT (socketpair (AF_UNIX, SOCK_STREAM, 0, sockfd) == 0);
+ pid_t child_pid = xclone (child_func, NULL, child_stack,
+ sizeof (child_stack),
+ CLONE_NEWUSER | CLONE_NEWNS | SIGCHLD);
+
+ xclose (sockfd[1]);
+ const int sock = sockfd[0];
+
+ char map_path[sizeof ("/proc//uid_map") + INT_STRLEN_BOUND (long)];
+ char map_buf[sizeof ("0 1") + INT_STRLEN_BOUND (long)];
+
+ snprintf (map_path, sizeof (map_path), "/proc/%ld/uid_map",
+ (long) child_pid);
+ snprintf (map_buf, sizeof (map_buf), "0 %ld 1", (long) getuid());
+ update_map (map_buf, map_path);
+
+ proc_setgroups_write ((long) child_pid, "deny");
+ snprintf (map_path, sizeof (map_path), "/proc/%ld/gid_map",
+ (long) child_pid);
+ snprintf (map_buf, sizeof (map_buf), "0 %ld 1", (long) getgid());
+ update_map (map_buf, map_path);
+
+ TEST_VERIFY_EXIT (send (sock, "1", 1, MSG_NOSIGNAL) == 1);
+ const int fd = recv_fd (sock);
+ TEST_VERIFY_EXIT (fd >= 0);
+ TEST_VERIFY_EXIT (fchdir (fd) == 0);
+
+ static char buf[2 * 10 + 1];
+ memset (buf, 'A', sizeof (buf));
+
+ /* Finally, call getcwd and check if it resulted in a buffer underflow. */
+ char * cwd = getcwd (buf + sizeof (buf) / 2, 1);
+ TEST_VERIFY (cwd == NULL);
+ TEST_VERIFY (errno == ERANGE);
+
+ for (int i = 0; i < sizeof (buf); i++)
+ if (buf[i] != 'A')
+ {
+ printf ("buf[%d] = %02x\n", i, (unsigned int) buf[i]);
+ support_record_failure ();
+ }
+
+ TEST_VERIFY_EXIT (send (sock, "a", 1, MSG_NOSIGNAL) == 1);
+ xclose (sock);
+ TEST_VERIFY_EXIT (xwaitpid (child_pid, NULL, 0) == child_pid);
+
+ return 0;
+}
+
+#define CLEANUP_HANDLER do_cleanup
+#include <support/test-driver.c>
--
2.34.1
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-01-24 6:51 UTC | newest]
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2022-01-24 6:50 [committed 2.34 0/6] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 1/6] support: Add helpers to create paths longer than PATH_MAX Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 2/6] stdlib: Sort tests in Makefile Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 3/6] stdlib: Fix formatting of tests list " Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 4/6] realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770] Siddhesh Poyarekar
2022-01-24 6:50 ` [committed 2.34 5/6] tst-realpath-toolong: Fix hurd build Siddhesh Poyarekar
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