forked from mirrors/nixpkgs
17be09a1f0
Patches have been imported into nixpkgs and manually edited to avoid merge conflicts on ChangeLog / NEWS files.
147 lines
4.5 KiB
Diff
147 lines
4.5 KiB
Diff
From 5460617d1567657621107d895ee2dd83bc1f88f2 Mon Sep 17 00:00:00 2001
|
|
From: Paul Pluzhnikov <ppluzhnikov@google.com>
|
|
Date: Tue, 8 May 2018 18:12:41 -0700
|
|
Subject: [PATCH] Fix BZ 22786: integer addition overflow may cause stack
|
|
buffer overflow when realpath() input length is close to SSIZE_MAX.
|
|
|
|
2018-05-09 Paul Pluzhnikov <ppluzhnikov@google.com>
|
|
|
|
[BZ #22786]
|
|
* stdlib/canonicalize.c (__realpath): Fix overflow in path length
|
|
computation.
|
|
* stdlib/Makefile (test-bz22786): New test.
|
|
* stdlib/test-bz22786.c: New test.
|
|
---
|
|
ChangeLog | 8 +++++
|
|
stdlib/Makefile | 2 +-
|
|
stdlib/canonicalize.c | 2 +-
|
|
stdlib/test-bz22786.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
4 files changed, 100 insertions(+), 2 deletions(-)
|
|
create mode 100644 stdlib/test-bz22786.c
|
|
|
|
diff --git a/stdlib/Makefile b/stdlib/Makefile
|
|
index af1643c..1ddb1f9 100644
|
|
--- a/stdlib/Makefile
|
|
+++ b/stdlib/Makefile
|
|
@@ -84,7 +84,7 @@ tests := tst-strtol tst-strtod testmb testrand testsort testdiv \
|
|
tst-cxa_atexit tst-on_exit test-atexit-race \
|
|
test-at_quick_exit-race test-cxa_atexit-race \
|
|
test-on_exit-race test-dlclose-exit-race \
|
|
- tst-makecontext-align
|
|
+ tst-makecontext-align test-bz22786
|
|
|
|
tests-internal := tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \
|
|
tst-tls-atexit tst-tls-atexit-nodelete
|
|
diff --git a/stdlib/canonicalize.c b/stdlib/canonicalize.c
|
|
index 4135f3f..390fb43 100644
|
|
--- a/stdlib/canonicalize.c
|
|
+++ b/stdlib/canonicalize.c
|
|
@@ -181,7 +181,7 @@ __realpath (const char *name, char *resolved)
|
|
extra_buf = __alloca (path_max);
|
|
|
|
len = strlen (end);
|
|
- if ((long int) (n + len) >= path_max)
|
|
+ if (path_max - n <= len)
|
|
{
|
|
__set_errno (ENAMETOOLONG);
|
|
goto error;
|
|
diff --git a/stdlib/test-bz22786.c b/stdlib/test-bz22786.c
|
|
new file mode 100644
|
|
index 0000000..e7837f9
|
|
--- /dev/null
|
|
+++ b/stdlib/test-bz22786.c
|
|
@@ -0,0 +1,90 @@
|
|
+/* Bug 22786: test for buffer overflow in realpath.
|
|
+ Copyright (C) 2018 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/>. */
|
|
+
|
|
+/* This file must be run from within a directory called "stdlib". */
|
|
+
|
|
+#include <errno.h>
|
|
+#include <limits.h>
|
|
+#include <stdio.h>
|
|
+#include <stdlib.h>
|
|
+#include <string.h>
|
|
+#include <unistd.h>
|
|
+#include <sys/stat.h>
|
|
+#include <sys/types.h>
|
|
+#include <support/test-driver.h>
|
|
+#include <libc-diag.h>
|
|
+
|
|
+static int
|
|
+do_test (void)
|
|
+{
|
|
+ const char dir[] = "bz22786";
|
|
+ const char lnk[] = "bz22786/symlink";
|
|
+
|
|
+ rmdir (dir);
|
|
+ if (mkdir (dir, 0755) != 0 && errno != EEXIST)
|
|
+ {
|
|
+ printf ("mkdir %s: %m\n", dir);
|
|
+ return EXIT_FAILURE;
|
|
+ }
|
|
+ if (symlink (".", lnk) != 0 && errno != EEXIST)
|
|
+ {
|
|
+ printf ("symlink (%s, %s): %m\n", dir, lnk);
|
|
+ return EXIT_FAILURE;
|
|
+ }
|
|
+
|
|
+ const size_t path_len = (size_t) INT_MAX + 1;
|
|
+
|
|
+ DIAG_PUSH_NEEDS_COMMENT;
|
|
+#if __GNUC_PREREQ (7, 0)
|
|
+ /* GCC 7 warns about too-large allocations; here we need such
|
|
+ allocation to succeed for the test to work. */
|
|
+ DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
|
|
+#endif
|
|
+ char *path = malloc (path_len);
|
|
+ DIAG_POP_NEEDS_COMMENT;
|
|
+
|
|
+ if (path == NULL)
|
|
+ {
|
|
+ printf ("malloc (%zu): %m\n", path_len);
|
|
+ return EXIT_UNSUPPORTED;
|
|
+ }
|
|
+
|
|
+ /* Construct very long path = "bz22786/symlink/aaaa....." */
|
|
+ char *p = mempcpy (path, lnk, sizeof (lnk) - 1);
|
|
+ *(p++) = '/';
|
|
+ memset (p, 'a', path_len - (path - p) - 2);
|
|
+ p[path_len - (path - p) - 1] = '\0';
|
|
+
|
|
+ /* This call crashes before the fix for bz22786 on 32-bit platforms. */
|
|
+ p = realpath (path, NULL);
|
|
+
|
|
+ if (p != NULL || errno != ENAMETOOLONG)
|
|
+ {
|
|
+ printf ("realpath: %s (%m)", p);
|
|
+ return EXIT_FAILURE;
|
|
+ }
|
|
+
|
|
+ /* Cleanup. */
|
|
+ unlink (lnk);
|
|
+ rmdir (dir);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+#define TEST_FUNCTION do_test
|
|
+#include <support/test-driver.c>
|
|
--
|
|
2.9.3
|
|
|