@matheusbsbs / matheus-bagliano / commits / b6c4380d6e

test-hashmap: check allocation computation for overflow

When we allocate the test_entry flex-struct, we have to add up all of the elements that go into the flex array. If these were to overflow a size_t, this would allocate a too-small buffer, which we would then overflow in our memcpy steps. Since this is just a test-helper, it probably doesn't matter in practice, but we should model the correct technique by using the st_add() macros. Unfortunately, we cannot use the FLEX_ALLOC() macros here, because we are stuffing two different buffers into a single flex array. While we're here, let's also swap out "malloc" for our error-checking "xmalloc", and use the preferred "sizeof(*var)" instead of "sizeof(type)". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Feb 14, 2018 at 13:06 UTC b6c4380d6e3170e21e6670248b7f332c57cb077c

1 file changed +1 -2

t/helper/test-hashmap.c

+1 -2

@@ -32,8 +32,7 @@ static int test_entry_cmp(const void *cmp_data,

32 static struct test_entry *alloc_test_entry(int hash, char *key, int klen,

33 char *value, int vlen)

34 {

35 - struct test_entry *entry = malloc(sizeof(struct test_entry) + klen

36 - + vlen + 2);

35 + struct test_entry *entry = xmalloc(st_add4(sizeof(*entry), klen, vlen, 2));

36 hashmap_entry_init(entry, hash);

37 memcpy(entry->key, key, klen + 1);

38 memcpy(entry->key + klen + 1, value, vlen + 1);