From: Frederic Lecaille <flecaille@haproxy.com>
Date: Thu, 28 May 2026 13:12:11 +0000 (+0200)
Subject: BUG/MEDIUM: quic: reset consecutive_losses on exit from recovery period (cubic)
X-Git-Tag: v3.4.0~62
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45ad1037d038f4dbabb0a159e68421a183d482d9;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: quic: reset consecutive_losses on exit from recovery period (cubic)

When exiting the recovery period and re-entering congestion avoidance,
the consecutive_losses counter was not reset. This meant that if a loss
event arrived immediately after the ACK that ended recovery, the counter
would still hold the value that triggered recovery, causing an immediate
re-entry into recovery (recovery -> CA -> recovery loop).

Resetting consecutive_losses to 0 on recovery exit matches the behavior
of resetting it on ACK in CA, ensuring a clean slate for the new
congestion avoidance period.

Must be backported to all versions.
---

diff --git a/src/quic_cc_cubic.c b/src/quic_cc_cubic.c
index 98ba360b8..5981d0427 100644
--- a/src/quic_cc_cubic.c
+++ b/src/quic_cc_cubic.c
@@ -607,6 +607,7 @@ static void quic_cc_cubic_rp_cb(struct quic_cc *cc, struct quic_cc_event *ev)
 
 		c->state = QUIC_CC_ST_CA;
 		c->recovery_start_time = TICK_ETERNITY;
+		c->consecutive_losses = 0;
 		break;
 	case QUIC_CC_EVT_LOSS:
 		break;