commit 5818f8a6693b3c0d95021f2ee58b69dcf848911c
Author: Roman Arutyunyan <arut@nginx.com>
Date:   Wed Feb 14 15:55:37 2024 +0400

    QUIC: fixed stream cleanup (ticket #2586).
    
    Stream connection cleanup handler ngx_quic_stream_cleanup_handler() calls
    ngx_quic_shutdown_stream() after which it resets the pointer from quic stream
    to the connection (sc->connection = NULL).  Previously if this call failed,
    sc->connection retained the old value, while the connection was freed by the
    application code.  This resulted later in a second attempt to close the freed
    connection, which lead to allocator double free error.
    
    The fix is to reset the sc->connection pointer in case of error.

diff --git a/src/event/quic/ngx_event_quic_streams.c b/src/event/quic/ngx_event_quic_streams.c
index df04d0f07..178b805e4 100644
--- a/src/event/quic/ngx_event_quic_streams.c
+++ b/src/event/quic/ngx_event_quic_streams.c
@@ -1097,6 +1097,7 @@ ngx_quic_stream_cleanup_handler(void *data)
                    "quic stream id:0x%xL cleanup", qs->id);
 
     if (ngx_quic_shutdown_stream(c, NGX_RDWR_SHUTDOWN) != NGX_OK) {
+        qs->connection = NULL;
         goto failed;
     }