--- /dev/null
+/* Test for (lack of) command execution in wordexp.
+ Copyright (C) 1997-2019 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
+ <https://www.gnu.org/licenses/>. */
+
+/* This test optionally counts PIDs in a PID namespace to detect
+ forks. Without kernel support for that, it will merely look at the
+ error codes from wordexp to check that no command execution
+ happens. */
+
+#include <sched.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/xunistd.h>
+#include <wordexp.h>
+
+/* Set to true if the test runs in a PID namespace and can therefore
+ use next_pid below. */
+static bool pid_tests_supported;
+
+/* The next PID, as returned from next_pid below. Only meaningful if
+ pid_tests_supported. */
+static pid_t expected_pid;
+
+/* Allocate the next PID and return it. The process is terminated.
+ Note that the test itself advances the next PID. */
+static pid_t
+next_pid (void)
+{
+ pid_t pid = xfork ();
+ if (pid == 0)
+ _exit (0);
+ xwaitpid (pid, NULL, 0);
+ return pid;
+}
+
+/* Check that evaluating PATTERN with WRDE_NOCMD results in
+ EXPECTED_ERROR. */
+static void
+expect_failure (const char *pattern, int expected_error)
+{
+ printf ("info: testing pattern: %s\n", pattern);
+ wordexp_t w;
+ TEST_COMPARE (wordexp (pattern, &w, WRDE_NOCMD), expected_error);
+ if (pid_tests_supported)
+ TEST_COMPARE (expected_pid++, next_pid ());
+}
+
+/* Run all the tests. Invoked with different IFS values. */
+static void
+run_tests (void)
+{
+ /* Integer overflow in division. */
+ {
+ static const char *const numbers[] = {
+ "0",
+ "1",
+ "65536",
+ "2147483648",
+ "4294967296"
+ "9223372036854775808",
+ "18446744073709551616",
+ "170141183460469231731687303715884105728",
+ "340282366920938463463374607431768211456",
+ NULL
+ };
+
+ for (const char *const *num = numbers; *num != NULL; ++num)
+ {
+ wordexp_t w;
+ char pattern[256];
+ snprintf (pattern, sizeof (pattern), "$[(-%s)/(-1)]", *num);
+ int ret = wordexp (pattern, &w, WRDE_NOCMD);
+ if (ret == 0)
+ {
+ /* If the call is successful, the result must match the
+ original number. */
+ TEST_COMPARE (w.we_wordc, 1);
+ TEST_COMPARE_STRING (w.we_wordv[0], *num);
+ TEST_COMPARE_STRING (w.we_wordv[1], NULL);
+ wordfree (&w);
+ }
+ else
+ /* Otherwise, the test must fail with a syntax error. */
+ TEST_COMPARE (ret, WRDE_SYNTAX);
+
+ /* In both cases, command execution is not permitted. */
+ if (pid_tests_supported)
+ TEST_COMPARE (expected_pid++, next_pid ());
+ }
+ }
+
+ /* (Lack of) command execution tests. */
+
+ expect_failure ("$(ls)", WRDE_CMDSUB);
+
+ /* Test for CVE-2014-7817. We test 3 combinations of command
+ substitution inside an arithmetic expression to make sure that
+ no commands are executed and error is returned. */
+ expect_failure ("$((`echo 1`))", WRDE_CMDSUB);
+ expect_failure ("$((1+`echo 1`))", WRDE_CMDSUB);
+ expect_failure ("$((1+$((`echo 1`))))", WRDE_CMDSUB);
+
+ expect_failure ("$[1/0]", WRDE_SYNTAX); /* BZ 18100. */
+}
+
+static void
+subprocess (void *closure)
+{
+ expected_pid = 2;
+ if (pid_tests_supported)
+ TEST_COMPARE (expected_pid++, next_pid ());
+
+ /* Check that triggering command execution via wordexp results in a
+ PID increase. */
+ if (pid_tests_supported)
+ {
+ wordexp_t w;
+ TEST_COMPARE (wordexp ("$(echo Test)", &w, 0), 0);
+ TEST_COMPARE (w.we_wordc, 1);
+ TEST_COMPARE_STRING (w.we_wordv[0], "Test");
+ TEST_COMPARE_STRING (w.we_wordv[1], NULL);
+ wordfree (&w);
+
+ pid_t n = next_pid ();
+ printf ("info: self-test resulted in PID %d (processes created: %d)\n",
+ (int) n, (int) (n - expected_pid));
+ TEST_VERIFY (n > expected_pid);
+ expected_pid = n + 1;
+ }
+
+ puts ("info: testing without IFS");
+ unsetenv ("IFS");
+ run_tests ();
+
+ puts ("info: testing with IFS");
+ TEST_COMPARE (setenv ("IFS", " \t\n", 1), 0);
+ run_tests ();
+}
+
+static int
+do_test (void)
+{
+ support_become_root ();
+
+#ifdef CLONE_NEWPID
+ if (unshare (CLONE_NEWPID) != 0)
+ printf ("warning: unshare (CLONE_NEW_PID) failed: %m\n"
+ "warning: This leads to reduced test coverage.\n");
+ else
+ pid_tests_supported = true;
+#else
+ printf ("warning: CLONE_NEW_PID not available.\n"
+ "warning: This leads to reduced test coverage.\n");
+#endif
+
+ /* CLONE_NEWPID only has an effect after fork. */
+ support_isolate_in_subprocess (subprocess, NULL);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
#define IFS " \n\t"
-extern int __register_atfork (void (*) (void), void (*) (void), void (*) (void), void *);
-
-static int __app_register_atfork (void (*prepare) (void), void (*parent) (void), void (*child) (void))
-{
- return __register_atfork (prepare, parent, child, __dso_handle);
-}
-
-/* Number of forks seen. */
-static int registered_forks;
-
-/* For each fork increment the fork count. */
-static void
-register_fork (void)
-{
- registered_forks++;
-}
-
struct test_case_struct
{
int retval;
{ WRDE_BADCHAR, NULL, "close-paren)", 0, 0, { NULL, }, IFS },
{ WRDE_BADCHAR, NULL, "{open-brace", 0, 0, { NULL, }, IFS },
{ WRDE_BADCHAR, NULL, "close-brace}", 0, 0, { NULL, }, IFS },
- { WRDE_CMDSUB, NULL, "$(ls)", WRDE_NOCMD, 0, { NULL, }, IFS },
{ WRDE_BADVAL, NULL, "$var", WRDE_UNDEF, 0, { NULL, }, IFS },
{ WRDE_BADVAL, NULL, "$9", WRDE_UNDEF, 0, { NULL, }, IFS },
{ WRDE_SYNTAX, NULL, "$[50+20))", 0, 0, { NULL, }, IFS },
{ WRDE_SYNTAX, NULL, "$((2+))", 0, 0, { NULL, }, IFS },
{ WRDE_SYNTAX, NULL, "`", 0, 0, { NULL, }, IFS },
{ WRDE_SYNTAX, NULL, "$((010+4+))", 0, 0, { NULL }, IFS },
- /* Test for CVE-2014-7817. We test 3 combinations of command
- substitution inside an arithmetic expression to make sure that
- no commands are executed and error is returned. */
- { WRDE_CMDSUB, NULL, "$((`echo 1`))", WRDE_NOCMD, 0, { NULL, }, IFS },
- { WRDE_CMDSUB, NULL, "$((1+`echo 1`))", WRDE_NOCMD, 0, { NULL, }, IFS },
- { WRDE_CMDSUB, NULL, "$((1+$((`echo 1`))))", WRDE_NOCMD, 0, { NULL, }, IFS },
{ WRDE_SYNTAX, NULL, "`\\", 0, 0, { NULL, }, IFS }, /* BZ 18042 */
{ WRDE_SYNTAX, NULL, "${", 0, 0, { NULL, }, IFS }, /* BZ 18043 */
{ WRDE_SYNTAX, NULL, "L${a:", 0, 0, { NULL, }, IFS }, /* BZ 18043#c4 */
- { WRDE_SYNTAX, NULL, "$[1/0]", WRDE_NOCMD, 0, {NULL, }, IFS }, /* BZ 18100 */
{ -1, NULL, NULL, 0, 0, { NULL, }, IFS },
};
return -1;
}
- /* If we are not allowed to do command substitution, we install
- fork handlers to verify that no forks happened. No forks should
- happen at all if command substitution is disabled. */
- if (__app_register_atfork (register_fork, NULL, NULL) != 0)
- {
- printf ("Failed to register fork handler.\n");
- return -1;
- }
-
for (test = 0; test_case[test].retval != -1; test++)
if (testit (&test_case[test]))
++fail;
++fail;
}
- /* Integer overflow in division. */
- {
- static const char *const numbers[] = {
- "0",
- "1",
- "65536",
- "2147483648",
- "4294967296"
- "9223372036854775808",
- "18446744073709551616",
- "170141183460469231731687303715884105728",
- "340282366920938463463374607431768211456",
- NULL
- };
-
- for (const char *const *num = numbers; *num; ++num)
- {
- wordexp_t p;
- char pattern[256];
- snprintf (pattern, sizeof (pattern), "$[(-%s)/(-1)]", *num);
- int ret = wordexp (pattern, &p, WRDE_NOCMD);
- if (ret == 0)
- {
- if (p.we_wordc != 1 || strcmp (p.we_wordv[0], *num) != 0)
- {
- printf ("Integer overflow for \"%s\" failed", pattern);
- ++fail;
- }
- wordfree (&p);
- }
- else if (ret != WRDE_SYNTAX)
- {
- printf ("Integer overflow for \"%s\" failed with %d",
- pattern, ret);
- ++fail;
- }
- }
- }
-
puts ("tests completed, now cleaning up");
/* Clean up */
fflush (NULL);
const char *words = at_page_end (tc->words);
- if (tc->flags & WRDE_NOCMD)
- registered_forks = 0;
-
if (tc->flags & WRDE_APPEND)
{
/* initial wordexp() call, to be appended to */
}
retval = wordexp (words, &we, tc->flags);
- if ((tc->flags & WRDE_NOCMD)
- && (registered_forks > 0))
- {
- printf ("FAILED fork called for WRDE_NOCMD\n");
- return 1;
- }
-
if (tc->flags & WRDE_DOOFFS)
start_offs = sav_we.we_offs;
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