From: Willy Tarreau <w@1wt.eu>
Date: Fri, 18 Jun 2021 08:33:47 +0000 (+0200)
Subject: MINOR: queue: update the stream's pend_pos before queuing it
X-Git-Tag: v2.5-dev1~66
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=901972e261da6747aff7ea2ebbd0f35aec6a8a08;p=thirdparty%2Fhaproxy.git

MINOR: queue: update the stream's pend_pos before queuing it

Since commit c7eedf7a5 ("MINOR: queue: reduce the locked area in
pendconn_add()") the stream's pend_pos is set out of the lock, after
the pendconn is queued. While this entry is only manipulated by the
stream itself and there is no bug caused by this right now, it's a
bit dangerous because another thread could decide to look at this
field during dequeuing and could randomly see something else. Also
in case of crashes, memory inspection wouldn't be as trustable.
Let's assign the pendconn before it can be found in the queue.
---

diff --git a/src/queue.c b/src/queue.c
index 6ff3404413..6c51dcd290 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -397,6 +397,7 @@ struct pendconn *pendconn_add(struct stream *strm)
 	p->px         = px;
 	p->strm       = strm;
 	p->strm_flags = strm->flags;
+	strm->pend_pos = p;
 
 	if (srv) {
 		unsigned int old_max, new_max;
@@ -430,7 +431,6 @@ struct pendconn *pendconn_add(struct stream *strm)
 		eb32_insert(&px->pendconns, &p->node);
 		HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &p->px->lock);
 	}
-	strm->pend_pos = p;
 
 	_HA_ATOMIC_INC(&px->totpend);
 	return p;