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From c92cbe6a93a7933abc59b2fe4bf96a32aff2c6d8 Mon Sep 17 00:00:00 2001
From: Noriko Hosoi <nhosoi@redhat.com>
Date: Tue, 9 Feb 2016 16:12:07 -0800
Subject: [PATCH 84/86] Ticket #48536 - Crash in slapi_get_object_extension

Description: The crashed was caused by the combination of psearch and
updating one of these group values: groupOfNames, groupOfUniqueNames,
groupOfCertificates, groupOfURL.

In the psearch, it creates aclpb in the acl plug-in and sets the original
pblock address in the aclpb. Then, psearch creates a copy of the pblock and
sets it in the psearch structure.  Now, the pblock address in aclpb and the
pblock address in the psearch structure do not match. The original pblock
itself is freed and the pblock area which address is stored in aclpb is not
guaranteed what is in it.

If nothing occurs, the freed pblock in aclpb is not accessed. But once one
of the group values is updated, the acl plug-in signature is updated and it
triggers to get aclpb from the pblock.

The acl_get_aclpb call accesses the freed pblock (e.g., NULL op) and it
crashes the server.

This patch checks the current pblock address and the pblock address in aclpb.
If they don't match, the address in aclpb is reassigned to the current pblock
address.

https://fedorahosted.org/389/ticket/48536

Reviewed by mreynolds@redhat.com (Thank you, Mark!!)

(cherry picked from commit 091a5f5daf3fa378f029e293c5358ae9be9f548e)
(cherry picked from commit 8a83a93977f13db36e42798a5eed041c1b3868a9)
---
 ldap/servers/plugins/acl/acl.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/ldap/servers/plugins/acl/acl.c b/ldap/servers/plugins/acl/acl.c
index 678a999..d56bed6 100644
--- a/ldap/servers/plugins/acl/acl.c
+++ b/ldap/servers/plugins/acl/acl.c
@@ -317,6 +317,13 @@ acl_access_allowed(
 		goto cleanup_and_ret;
 	}
 
+	if (pb != aclpb->aclpb_pblock) {
+		slapi_log_error(SLAPI_LOG_FATAL, plugin_name,
+		                "acl_access_allowed: Resetting aclpb_pblock 0x%x to pblock addr 0x%x\n",
+		                aclpb->aclpb_pblock, pb);
+		aclpb->aclpb_pblock = pb;
+	}
+
 	if ( !aclpb->aclpb_curr_entry_sdn ) {
 		slapi_log_error	( SLAPI_LOG_FATAL, plugin_name,	 "NULL aclpb_curr_entry_sdn \n" );
 		ret_val	= LDAP_OPERATIONS_ERROR;
@@ -932,6 +939,13 @@ acl_read_access_allowed_on_entry (
 							tnf_string,end,"aclpb error");
 		return LDAP_OPERATIONS_ERROR;
 	}
+	 
+	if (pb != aclpb->aclpb_pblock) {
+		slapi_log_error(SLAPI_LOG_ACL, plugin_name,
+		                "acl_read_access_allowed_on_entry: Resetting aclpb_pblock 0x%x to pblock addr 0x%x\n",
+		                aclpb->aclpb_pblock, pb);
+		aclpb->aclpb_pblock = pb;
+	}
 
 	/*
 	 * Am I	a anonymous dude ? then	we can use our anonympous profile
-- 
2.4.3