+2014-11-19 Carlos O'Donell <carlos@redhat.com>
+ Florian Weimer <fweimer@redhat.com>
+ Joseph Myers <joseph@codesourcery.com>
+ Adam Conrad <adconrad@0c3.net>
+ Andreas Schwab <schwab@suse.de>
+ Brooks <bmoses@google.com>
+
+ [BZ #17625]
+ * wordexp-test.c (__dso_handle): Add prototype.
+ (__register_atfork): Likewise.
+ (__app_register_atfork): New function.
+ (registered_forks): New global.
+ (register_fork): New function.
+ (test_case): Add 3 new tests for WRDE_CMDSUB.
+ (main): Call __app_register_atfork.
+ (testit): If WRDE_NOCMD set registered_forks to zero, run test, and if
+ fork count is non-zero fail the test.
+ * posix/wordexp.c (exec_comm): Return WRDE_CMDSUB if WRDE_NOCMD flag
+ is set.
+ (parse_dollars): Remove check for WRDE_NOCMD.
+ (parse_dquote): Likewise.
+
2014-11-10 Renlin Li <Renlin.Li@arm.com>
[BZ #17555]
* The following bugs are resolved with this release:
- 17266, 17370, 17371, 17460, 17485, 17555.
+ 17266, 17370, 17371, 17460, 17485, 17555, 17625.
+
+* CVE-2104-7817 The wordexp function could ignore the WRDE_NOCMD flag
+ under certain input conditions resulting in the execution of a shell for
+ command substitution when the applicaiton did not request it. The
+ implementation now checks WRDE_NOCMD immediately before executing the
+ shell and returns the error WRDE_CMDSUB as expected.
+
\f
Version 2.20
#define IFS " \n\t"
+extern void *__dso_handle __attribute__ ((__weak__, __visibility__ ("hidden")));
+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 == NULL ? NULL : __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_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 },
{ -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;
printf ("Test %d (%s): ", ++tests, tc->words);
+ if (tc->flags & WRDE_NOCMD)
+ registered_forks = 0;
+
if (tc->flags & WRDE_APPEND)
{
/* initial wordexp() call, to be appended to */
}
retval = wordexp (tc->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;
pid_t pid;
int noexec = 0;
+ /* Do nothing if command substitution should not succeed. */
+ if (flags & WRDE_NOCMD)
+ return WRDE_CMDSUB;
+
/* Don't fork() unless necessary */
if (!comm || !*comm)
return 0;
}
}
- if (flags & WRDE_NOCMD)
- return WRDE_CMDSUB;
-
(*offset) += 2;
return parse_comm (word, word_length, max_length, words, offset, flags,
quoted? NULL : pwordexp, ifs, ifs_white);
break;
case '`':
- if (flags & WRDE_NOCMD)
- return WRDE_CMDSUB;
-
++(*offset);
error = parse_backtick (word, word_length, max_length, words,
offset, flags, NULL, NULL, NULL);
break;
case '`':
- if (flags & WRDE_NOCMD)
- {
- error = WRDE_CMDSUB;
- goto do_error;
- }
-
++words_offset;
error = parse_backtick (&word, &word_length, &max_length, words,
&words_offset, flags, pwordexp, ifs,