From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Ym6YL8Hh; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id B2F075A0262 for ; Thu, 09 Jul 2026 00:32:11 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783549930; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aEVdnGhxI5ySgmljZ1YYQxQdxtZN3IqtLtdeijSHrwc=; b=Ym6YL8HhPmETZudxfVTTQwHBbHfjjS6+vegtYFacOc//bwAAGqUJd723IxwcZCChRoTUCC f3eMYiCbiEdB+4SNvcC98TWpmwJ/oYH2D46LLqmHpwT1r30XQ5RQSk3WieycRAttjbIrW9 0iLU4v/gcHHYswo9ICTzHtMRDnp84n0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-186-R6xBDIKaPdmoYWd5yQ9pEA-1; Wed, 08 Jul 2026 18:32:09 -0400 X-MC-Unique: R6xBDIKaPdmoYWd5yQ9pEA-1 X-Mimecast-MFC-AGG-ID: R6xBDIKaPdmoYWd5yQ9pEA_1783549928 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2D0251956061; Wed, 8 Jul 2026 22:32:08 +0000 (UTC) Received: from jmaloy-thinkpadp16vgen1.rmtcaqc.csb (unknown [10.22.88.44]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 515321955F75; Wed, 8 Jul 2026 22:32:07 +0000 (UTC) From: Jon Maloy To: sbrivio@redhat.com, david@gibson.dropbear.id.au, jmaloy@redhat.com, passt-dev@passt.top Subject: [PATCH 2/7] udp_vu: Assert iov_tail_clone() return before assigning to msg_iovlen Date: Wed, 8 Jul 2026 18:31:58 -0400 Message-ID: <20260708223203.885345-3-jmaloy@redhat.com> In-Reply-To: <20260708223203.885345-1-jmaloy@redhat.com> References: <20260708223203.885345-1-jmaloy@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: TQWrurt0sSlbXg520Dj32i8xMdDUPvApNaj6DVX5ilo_1783549928 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: 43QMXAS4R325GNKA336GGTPRYE6SW7BC X-Message-ID-Hash: 43QMXAS4R325GNKA336GGTPRYE6SW7BC X-MailFrom: jmaloy@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: iov_tail_clone() returns ssize_t, but its return value was assigned directly to msg.msg_iovlen which is size_t. Add an assert to document the invariant that the clone into a VIRTQUEUE_MAX_SIZE array cannot fail. Signed-off-by: Jon Maloy --- udp_vu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/udp_vu.c b/udp_vu.c index e4fb1057..5d6f45ec 100644 --- a/udp_vu.c +++ b/udp_vu.c @@ -67,11 +67,14 @@ static ssize_t udp_vu_sock_recv(struct iov_tail *payload, size_t *cnt, int s) struct iovec msg_iov[VIRTQUEUE_MAX_SIZE]; struct msghdr msg = { 0 }; size_t iov_used; + ssize_t iovlen; ssize_t dlen; + iovlen = iov_tail_clone(msg_iov, ARRAY_SIZE(msg_iov), payload); + assert(iovlen >= 0); + msg.msg_iov = msg_iov; - msg.msg_iovlen = iov_tail_clone(msg.msg_iov, ARRAY_SIZE(msg_iov), - payload); + msg.msg_iovlen = iovlen; /* read data from the socket */ dlen = recvmsg(s, &msg, 0); -- 2.52.0