OPENSSL_LH_flush(): assign NULL after freeing

OPENSSL_LH_flush() frees the linked lists for each slot, but didn't
set the list head to NULL after doing so, with the result that an
operation that affects these lists is likely to cause a crash.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8781)

1 files changed, 1 insertions, 0 deletions

diff --git a/crypto/lhash/lhash.c b/crypto/lhash/lhash.c
index aa0ca1c957..e3c7ac456b 100644
--- a/crypto/lhash/lhash.c
+++ b/crypto/lhash/lhash.c
@@ -98,6 +98,7 @@ void OPENSSL_LH_flush(OPENSSL_LHASH *lh)
             OPENSSL_free(n);
             n = nn;
         }
+        lh->b[i] = NULL;
     }
 }