From: Richard Levitte <levitte@openssl.org>
Date: Tue, 25 Jul 2000 16:56:39 +0000 (+0000)
Subject: Avoid a race condition if another thread happens to remove the error
X-Git-Tag: OpenSSL-engine-0_9_6-beta1~17^2~14
X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=34f0fe9de0597bd933f2dd13ae26843ed5273922;ds=sidebyside

Avoid a race condition if another thread happens to remove the error
state at the same time.
---

diff --git a/crypto/err/err.c b/crypto/err/err.c
index ad062a9022..7ce9e8fb9a 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -652,12 +652,15 @@ void ERR_remove_state(unsigned long pid)
 		pid=(unsigned long)CRYPTO_thread_id();
 	tmp.pid=pid;
 	CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-	p=(ERR_STATE *)lh_delete(thread_hash,&tmp);
-	if (lh_num_items(thread_hash) == 0)
+	if (thread_hash)
 		{
-		/* make sure we don't leak memory */
-		lh_free(thread_hash);
-		thread_hash = NULL;
+		p=(ERR_STATE *)lh_delete(thread_hash,&tmp);
+		if (lh_num_items(thread_hash) == 0)
+			{
+			/* make sure we don't leak memory */
+			lh_free(thread_hash);
+			thread_hash = NULL;
+			}
 		}
 	CRYPTO_w_unlock(CRYPTO_LOCK_ERR);