Move free from cbb_init() to only CBB_init().
CBB_init_fixed() should not call free because it can lead to use after
free or double free bugs. The caller should be responsible for
creating and destroying the buffer.
In the current code, ssl3_get_v2_client_hello() may free s->init_buf->data
via CBB_init_fixed(). It can also be freed via SSL_free(s) since
ssl3_get_v2_client_hello() doesn't set it to NULL and CBB_init_fixed()
can't set the caller's pointer to NULL.
Change-Id: Ia05a67ae25af7eb4fb04f08f20d50d912b41e38b
diff --git a/crypto/bytestring/cbb.c b/crypto/bytestring/cbb.c
index 4428836..7dc6342 100644
--- a/crypto/bytestring/cbb.c
+++ b/crypto/bytestring/cbb.c
@@ -25,7 +25,6 @@
base = OPENSSL_malloc(sizeof(struct cbb_buffer_st));
if (base == NULL) {
- OPENSSL_free(buf);
return 0;
}
@@ -48,7 +47,12 @@
return 0;
}
- return cbb_init(cbb, buf, initial_capacity);
+ if (!cbb_init(cbb, buf, initial_capacity)) {
+ OPENSSL_free(buf);
+ return 0;
+ }
+
+ return 1;
}
int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len) {
