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 d3920ce8da7981b9eac8b1bfe4dbd460f79d273a..a1fe015df4a41065ad7e2e87941555fc55b85518 100644 (file)
--- 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