posix: Fix some crashes in wordexp [BZ #18096]

Without these fixes, the first three included tests segfault (on a
NULL dereference); the fourth aborts on an assertion, which is itself
unnecessary.

Signed-off-by: Julian Squires <julian@cipht.net>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

diff --git a/posix/wordexp-test.c b/posix/wordexp-test.c
index f7a5911..bae27d6 100644 (file)
--- a/posix/wordexp-test.c
+++ b/posix/wordexp-test.c
@@ -117,6 +117,8 @@ struct test_case_struct
     { 0, NULL, "$((010+0x10))", 0, 1, { "24" }, IFS },
     { 0, NULL, "$((-010+0x10))", 0, 1, { "8" }, IFS },
     { 0, NULL, "$((-0x10+010))", 0, 1, { "-8" }, IFS },
+    { 0, NULL, "$(())", 0, 1, { "0", }, IFS },
+    { 0, NULL, "$[]", 0, 1, { "0", }, IFS },
 
     /* Advanced parameter expansion */
     { 0, NULL, "${var:-bar}", 0, 1, { "bar", }, IFS },
@@ -138,6 +140,8 @@ struct test_case_struct
     { 0, "12345", "${#var}", 0, 1, { "5", }, IFS },
     { 0, NULL, "${var:-'}'}", 0, 1, { "}", }, IFS },
     { 0, NULL, "${var-}", 0, 0, { NULL }, IFS },
+    { 0, NULL, "${a?}", 0, 0, { NULL, }, IFS },
+    { 0, NULL, "${#a=}", 0, 1, { "0", }, IFS },
 
     { 0, "pizza", "${var#${var}}", 0, 0, { NULL }, IFS },
     { 0, "pepperoni", "${var%$(echo oni)}", 0, 1, { "pepper" }, IFS },

diff --git a/posix/wordexp.c b/posix/wordexp.c
index 0da98f5..b34c4a9 100644 (file)
--- a/posix/wordexp.c
+++ b/posix/wordexp.c
@@ -720,7 +720,7 @@ parse_arith (char **word, size_t *word_length, size_t *max_length,
              ++(*offset);
 
              /* Go - evaluate. */
-             if (*expr && eval_expr (expr, &numresult) != 0)
+             if (expr && eval_expr (expr, &numresult) != 0)
                {
                  free (expr);
                  return WRDE_SYNTAX;
@@ -758,7 +758,7 @@ parse_arith (char **word, size_t *word_length, size_t *max_length,
              long int numresult = 0;
 
              /* Go - evaluate. */
-             if (*expr && eval_expr (expr, &numresult) != 0)
+             if (expr && eval_expr (expr, &numresult) != 0)
                {
                  free (expr);
                  return WRDE_SYNTAX;
@@ -1790,7 +1790,7 @@ envsubst:
            {
              const char *str = pattern;
 
-             if (str[0] == '\0')
+             if (!str || str[0] == '\0')
                str = _("parameter null or not set");
 
              __fxprintf (NULL, "%s: %s\n", env, str);
@@ -1883,10 +1883,7 @@ envsubst:
                        _itoa_word (value ? strlen (value) : 0,
                                    &param_length[20], 10, 0));
       if (free_value)
-       {
-         assert (value != NULL);
-         free (value);
-       }
+       free (value);
 
       return *word ? 0 : WRDE_NOSPACE;
     }