[389-commits] [389-ds-base] branch 389-ds-base-1.4.2 updated: Ticket 50905 - intermittent SSL hang with rhds

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tbordaz pushed a commit to branch 389-ds-base-1.4.2
in repository 389-ds-base.

The following commit(s) were added to refs/heads/389-ds-base-1.4.2 by this push:
     new 03103f1  Ticket 50905 - intermittent SSL hang with rhds
03103f1 is described below

commit 03103f19f7daa0064aad70497f50660f2c60bcc5
Author: Thierry Bordaz 
AuthorDate: Fri Apr 3 15:23:10 2020 +0200

Ticket 50905 - intermittent SSL hang with rhds

Bug Description:
    	On a successfull sasl bind, a new IO layer (sasl_io_enable) is registered on top of
    	the connection. Then sasl bind sends the successful result. Registration is
    	done while sasl bind thread holds c_mutex but result is sent while the c_mutex
    	is released.

If a new operation comes in just after c_mutex was released it is
    	possible that sasl bind sends the result while the new IO layer is pushed.
            IO layers is partially initialized at that time. It can create sigseg or
    	deadlock or...

Fix Description:
    	The fix is to protect the send result from IO layer push.
    	i.e. move send_ldap_result into c_mutex

https://pagure.io/389-ds-base/issue/50905

Reviewed by: Mark Reynolds (Thanks !!)

Platforms tested: F29

Flag Day: no

Doc impact: no
---
 ldap/servers/slapd/saslbind.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/ldap/servers/slapd/saslbind.c b/ldap/servers/slapd/saslbind.c
index 7cad0db..6a43d2e 100644
--- a/ldap/servers/slapd/saslbind.c
+++ b/ldap/servers/slapd/saslbind.c
@@ -1118,12 +1118,16 @@ sasl_check_result:
             /* Enable SASL I/O on the connection */
             pthread_mutex_lock(&(pb_conn->c_mutex));
             connection_set_io_layer_cb(pb_conn, sasl_io_enable, NULL, NULL);
+
+            /* send successful result before sasl_io_enable can be pushed by another incoming op */
+            send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
+
             pthread_mutex_unlock(&(pb_conn->c_mutex));
+        } else {
+            /* send successful result */
+            send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
         }

-        /* send successful result */
-        send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
-
         /* remove the sasl data from the pblock */
         slapi_pblock_set(pb, SLAPI_BIND_RET_SASLCREDS, NULL);