From: Olivier Houchard <ohouchard@haproxy.com>
Date: Tue, 9 Jul 2019 15:28:51 +0000 (+0200)
Subject: BUG/MEDIUM: checks: Don't attempt to read if we destroyed the connection.
X-Git-Tag: v2.1-dev1~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc89ad8d94246eca064b87e76c1897f6a950f6fb;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: checks: Don't attempt to read if we destroyed the connection.

In event_srv_chk_io(), only call __event_srv_chk_r() if we did not subscribe
for reading, and if wake_srv_chk() didn't return -1, as it would mean it
just destroyed the connection and the conn_stream, and attempting to use
those to recv data would lead to a crash.

This should be backported to 1.9 and 2.0.
---

diff --git a/src/checks.c b/src/checks.c
index d3920ce8da..a1fe015df4 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -716,10 +716,11 @@ static struct task *event_srv_chk_io(struct task *t, void *ctx, unsigned short s
 	struct check *check = ctx;
 	struct conn_stream *cs = check->cs;
 	struct email_alertq *q = container_of(check, typeof(*q), check);
+	int ret = 0;
 
 	if (!(check->wait_list.events & SUB_RETRY_SEND))
-		wake_srv_chk(cs);
-	if (!(check->wait_list.events & SUB_RETRY_RECV)) {
+		ret = wake_srv_chk(cs);
+	if (ret == 0 && !(check->wait_list.events & SUB_RETRY_RECV)) {
 		if (check->server)
 			HA_SPIN_LOCK(SERVER_LOCK, &check->server->lock);
 		else