diff options
Diffstat (limited to 'posix')
| -rw-r--r-- | posix/wordexp-test.c | 44 | ||||
| -rw-r--r-- | posix/wordexp.c | 16 |
2 files changed, 48 insertions, 12 deletions
diff --git a/posix/wordexp-test.c b/posix/wordexp-test.c index 4957006..bdd65e4 100644 --- a/posix/wordexp-test.c +++ b/posix/wordexp-test.c @@ -27,6 +27,25 @@ #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; @@ -206,6 +225,12 @@ struct test_case_struct { 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 }, }; @@ -258,6 +283,15 @@ main (int argc, char *argv[]) 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; @@ -367,6 +401,9 @@ testit (struct test_case_struct *tc) 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 */ @@ -378,6 +415,13 @@ testit (struct test_case_struct *tc) } 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; diff --git a/posix/wordexp.c b/posix/wordexp.c index b6b65dd..26f3a26 100644 --- a/posix/wordexp.c +++ b/posix/wordexp.c @@ -893,6 +893,10 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, 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; @@ -2082,9 +2086,6 @@ parse_dollars (char **word, size_t *word_length, size_t *max_length, } } - 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); @@ -2196,9 +2197,6 @@ parse_dquote (char **word, size_t *word_length, size_t *max_length, break; case '`': - if (flags & WRDE_NOCMD) - return WRDE_CMDSUB; - ++(*offset); error = parse_backtick (word, word_length, max_length, words, offset, flags, NULL, NULL, NULL); @@ -2357,12 +2355,6 @@ wordexp (const char *words, wordexp_t *pwordexp, int flags) 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, |