From: Pavan Deolasee <pavan.deolasee@gmail.com>
Date: Fri, 6 May 2016 12:36:37 +0000 (+0530)
Subject: Fix a memory leak in GTM proxy
X-Git-Tag: XL_10_R1BETA1~670
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=166b0280b0c8ac61c9a70bed5aaa83c98f9fc32c;p=postgres-xl.git

Fix a memory leak in GTM proxy

When two lists are concatnated, we might leak header of the second list since
only the list cells are concatnated. We must be careful not to free the list if
list_concat returned the to-be-concatnated list as-is.
---

diff --git a/src/gtm/proxy/proxy_main.c b/src/gtm/proxy/proxy_main.c
index 871280fa89..e03e3e8b34 100644
--- a/src/gtm/proxy/proxy_main.c
+++ b/src/gtm/proxy/proxy_main.c
@@ -2441,6 +2441,14 @@ GTMProxy_ProcessPendingCommands(GTMProxy_ThreadInfo *thrinfo)
 				 */
 				thrinfo->thr_processed_commands = gtm_list_concat(thrinfo->thr_processed_commands,
 						thrinfo->thr_pending_commands[ii]);
+				/*
+				 * Free the list header of the second list, unless
+				 * gtm_list_concat actually returned the second list as-is
+				 * because the first list was empty
+				 */
+				if ((thrinfo->thr_processed_commands != thrinfo->thr_pending_commands[ii]) &&
+					(thrinfo->thr_pending_commands[ii] != gtm_NIL))
+					pfree(thrinfo->thr_pending_commands[ii]);
 				thrinfo->thr_pending_commands[ii] = gtm_NIL;
 				break;
 
@@ -2472,6 +2480,14 @@ GTMProxy_ProcessPendingCommands(GTMProxy_ThreadInfo *thrinfo)
 				 */
 				thrinfo->thr_processed_commands = gtm_list_concat(thrinfo->thr_processed_commands,
 						thrinfo->thr_pending_commands[ii]);
+				/*
+				 * Free the list header of the second list, unless
+				 * gtm_list_concat actually returned the second list as-is
+				 * because the first list was empty
+				 */
+				if ((thrinfo->thr_processed_commands != thrinfo->thr_pending_commands[ii]) &&
+					(thrinfo->thr_pending_commands[ii] != gtm_NIL))
+					pfree(thrinfo->thr_pending_commands[ii]);
 				thrinfo->thr_pending_commands[ii] = gtm_NIL;
 				break;
 
@@ -2506,6 +2522,14 @@ GTMProxy_ProcessPendingCommands(GTMProxy_ThreadInfo *thrinfo)
 				 */
 				thrinfo->thr_processed_commands = gtm_list_concat(thrinfo->thr_processed_commands,
 						thrinfo->thr_pending_commands[ii]);
+				/*
+				 * Free the list header of the second list, unless
+				 * gtm_list_concat actually returned the second list as-is
+				 * because the first list was empty
+				 */
+				if ((thrinfo->thr_processed_commands != thrinfo->thr_pending_commands[ii]) &&
+					(thrinfo->thr_pending_commands[ii] != gtm_NIL))
+					pfree(thrinfo->thr_pending_commands[ii]);
 				thrinfo->thr_pending_commands[ii] = gtm_NIL;
 				break;
 
@@ -2537,6 +2561,14 @@ GTMProxy_ProcessPendingCommands(GTMProxy_ThreadInfo *thrinfo)
 				 */
 				thrinfo->thr_processed_commands = gtm_list_concat(thrinfo->thr_processed_commands,
 						thrinfo->thr_pending_commands[ii]);
+				/*
+				 * Free the list header of the second list, unless
+				 * gtm_list_concat actually returned the second list as-is
+				 * because the first list was empty
+				 */
+				if ((thrinfo->thr_processed_commands != thrinfo->thr_pending_commands[ii]) &&
+					(thrinfo->thr_pending_commands[ii] != gtm_NIL))
+					pfree(thrinfo->thr_pending_commands[ii]);
 				thrinfo->thr_pending_commands[ii] = gtm_NIL;
 				break;