From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Thu, 12 Nov 2026 14:31:14 +0000 (+0100)
Subject: BUG/MINOR: h3: close connection on response start-line alloc failure
X-Git-Tag: v3.5-dev12~27
X-Git-Url: https://git.kaiwu.me/%7B@url%7D?a=commitdiff_plain;h=cf19fffaed0c950c64904fe8e045a0df5a8db53d;p=haproxy.git

BUG/MINOR: h3: close connection on response start-line alloc failure

On QUIC backend side, correct the error handling when HTX start-line
cannot be allocated during HTTP/3 response parsing.

Previously, a stream error would be reported with H3_MESSAGE_ERROR. Now,
h3_resp_headers_to_htx() only returns a default negative value without
any explicit error code. This results in a connection level error using
H3_INTERNAL_ERROR, generated at the end of h3_rcv_buf().

This pattern is already used on request parsing. It is necessary to
close the connection asap on memory exhaustion while differentiating
between a peer protocol violation and an haproxy internal error.

This must be backported up to 3.3.
---

diff --git a/src/h3.c b/src/h3.c
index 0040b3579..278bafccd 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -1426,7 +1426,6 @@ static ssize_t h3_resp_headers_to_htx(struct qcs *qcs, const struct buffer *buf,
 	sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, ist("HTTP/3.0"), status, ist(""));
 	if (!sl) {
 		TRACE_ERROR("cannot allocate HTX start-line", H3_EV_RX_FRAME|H3_EV_RX_HDR, qcs->qcc->conn, qcs);
-		h3s->err = H3_ERR_MESSAGE_ERROR;
 		len = -1;
 		goto out;
 	}