From 8e1217c46dcd66efa1cc2ca2d2b43d85db24b416 Mon Sep 17 00:00:00 2001 From: Sergey Kandaurov Date: Fri, 20 Oct 2023 18:05:07 +0400 Subject: [PATCH] QUIC: prevented generating ACK frames with discarded keys. Previously it was possible to generate ACK frames using formally discarded protection keys, in particular, when acknowledging a client Handshake packet used to complete the TLS handshake and to discard handshake protection keys. As it happens late in packet processing, it could be possible to generate ACK frames after the keys were already discarded. ACK frames are generated from ngx_quic_ack_packet(), either using a posted push event, which envolves ngx_quic_generate_ack() as a part of the final packet assembling, or directly in ngx_quic_ack_packet(), such as when there is no room to add a new ACK range or when the received packet is out of order. The added keys availability check is used to avoid generating late ACK frames in both cases. --- src/event/quic/ngx_event_quic_ack.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/event/quic/ngx_event_quic_ack.c b/src/event/quic/ngx_event_quic_ack.c index 23c9af348..a7fd85d20 100644 --- a/src/event/quic/ngx_event_quic_ack.c +++ b/src/event/quic/ngx_event_quic_ack.c @@ -907,6 +907,10 @@ ngx_quic_ack_packet(ngx_connection_t *c, ngx_quic_header_t *pkt) " nranges:%ui", pkt->pn, (int64_t) ctx->largest_range, ctx->first_range, ctx->nranges); + if (!ngx_quic_keys_available(qc->keys, ctx->level, 1)) { + return NGX_OK; + } + prev_pending = ctx->pending_ack; if (pkt->need_ack) {