Merge branch 'rs/nth-parent-parse'
authorJunio C Hamano <gitster@pobox.com>
Mon, 7 Oct 2019 02:32:57 +0000 (11:32 +0900)
committerJunio C Hamano <gitster@pobox.com>
Mon, 7 Oct 2019 02:32:57 +0000 (11:32 +0900)
The object name parser for "Nth parent" syntax has been made more
robust against integer overflows.

* rs/nth-parent-parse:
  sha1-name: check for overflow of N in "foo^N" and "foo~N"
  rev-parse: demonstrate overflow of N for "foo^N" and "foo~N"

sha1-name.c
t/t1506-rev-parse-diagnosis.sh

index c665e3f..7a047e9 100644 (file)
@@ -1160,13 +1160,22 @@ static enum get_oid_result get_oid_1(struct repository *r,
        }
 
        if (has_suffix) {
-               int num = 0;
+               unsigned int num = 0;
                int len1 = cp - name;
                cp++;
-               while (cp < name + len)
-                       num = num * 10 + *cp++ - '0';
+               while (cp < name + len) {
+                       unsigned int digit = *cp++ - '0';
+                       if (unsigned_mult_overflows(num, 10))
+                               return MISSING_OBJECT;
+                       num *= 10;
+                       if (unsigned_add_overflows(num, digit))
+                               return MISSING_OBJECT;
+                       num += digit;
+               }
                if (!num && len1 == len - 1)
                        num = 1;
+               else if (num > INT_MAX)
+                       return MISSING_OBJECT;
                if (has_suffix == '^')
                        return get_parent(r, name, len1, oid, num);
                /* else if (has_suffix == '~') -- goes without saying */
index 21a9c8f..624d0a5 100755 (executable)
@@ -214,4 +214,12 @@ test_expect_success 'arg before dashdash must be a revision (ambiguous)' '
        test_cmp expect actual
 '
 
+test_expect_success 'reject Nth parent if N is too high' '
+       test_must_fail git rev-parse HEAD^100000000000000000000000000000000
+'
+
+test_expect_success 'reject Nth ancestor if N is too high' '
+       test_must_fail git rev-parse HEAD~100000000000000000000000000000000
+'
+
 test_done