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c6e0b0b5b0
It sync with gnulib version ae9fb3d66. The testcase for BZ#23741
(stdlib/test-bz22786.c) is adjusted to check also for ENOMEM.
The patch fixes multiple realpath issues:
- Portability fixes for errno clobbering on free (BZ#10635). The
function does not call free directly anymore, although it might be
done through scratch_buffer_free. The free errno clobbering is
being tracked by BZ#17924.
- Pointer arithmetic overflows in realpath (BZ#26592).
- Realpath cyclically call __alloca(path_max) to consume too much
stack space (BZ#26341).
- Realpath mishandles EOVERFLOW; stat not needed anyway (BZ#24970).
The check is done through faccessat now.
Checked on x86_64-linux-gnu and i686-linux-gnu.
80 lines
2.6 KiB
C
80 lines
2.6 KiB
C
/* Bug 22786: test for buffer overflow in realpath.
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Copyright (C) 2018-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* This file must be run from within a directory called "stdlib". */
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#include <errno.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <support/blob_repeat.h>
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#include <support/check.h>
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#include <support/support.h>
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#include <support/temp_file.h>
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#include <support/test-driver.h>
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#include <libc-diag.h>
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static int
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do_test (void)
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{
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char *dir = support_create_temp_directory ("bz22786.");
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char *lnk = xasprintf ("%s/symlink", dir);
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const size_t path_len = (size_t) INT_MAX + strlen (lnk) + 1;
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struct support_blob_repeat repeat
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= support_blob_repeat_allocate ("a", 1, path_len);
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char *path = repeat.start;
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if (path == NULL)
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{
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printf ("Repeated allocation (%zu bytes): %m\n", path_len);
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/* On 31-bit s390 the malloc will always fail as we do not have
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so much memory, and we want to mark the test unsupported.
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Likewise on systems with little physical memory the test will
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fail and should be unsupported. */
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return EXIT_UNSUPPORTED;
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}
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TEST_VERIFY_EXIT (symlink (".", lnk) == 0);
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/* Construct very long path = "/tmp/bz22786.XXXX/symlink/aaaa....." */
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char *p = mempcpy (path, lnk, strlen (lnk));
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*(p++) = '/';
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p[path_len - (p - path) - 1] = '\0';
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/* This call crashes before the fix for bz22786 on 32-bit platforms. */
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p = realpath (path, NULL);
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TEST_VERIFY (p == NULL);
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/* For 64-bit platforms readlink return ENAMETOOLONG, while for 32-bit
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realpath will try to allocate a buffer larger than PTRDIFF_MAX. */
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TEST_VERIFY (errno == ENOMEM || errno == ENAMETOOLONG);
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/* Cleanup. */
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unlink (lnk);
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support_blob_repeat_free (&repeat);
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free (lnk);
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free (dir);
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return 0;
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}
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#include <support/test-driver.c>
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