From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1D1DC87FC5 for ; Mon, 21 Jul 2025 06:01:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1udjZG-0008Gh-15; Mon, 21 Jul 2025 02:00:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1udjYt-0008Ai-Td for qemu-devel@nongnu.org; Mon, 21 Jul 2025 01:59:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1udjYr-000664-Sf for qemu-devel@nongnu.org; Mon, 21 Jul 2025 01:59:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753077580; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1aXwN4h+5NWvUK9uc0dLGqkRb9fIsj01GkAtL71dIXQ=; b=FFDWM4mXuf8CtweB/D7ccP9Wmmq7oXle88J3hxapBstJ/Ml5O8LWb43RZlKtvtvBC3UT02 RA4sIdc6TvVQvOA7lTw6zZFgMEf2z3UBSWJHDEfc8ztRiIf8ZBbTXSFpzoi8Zu7NJJCuT+ KWPQFTAJkaxKmjhPBtxRzFadpFR8br4= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-643-UiE96Yw1OeCJfFM-hUfW3g-1; Mon, 21 Jul 2025 01:59:38 -0400 X-MC-Unique: UiE96Yw1OeCJfFM-hUfW3g-1 X-Mimecast-MFC-AGG-ID: UiE96Yw1OeCJfFM-hUfW3g_1753077578 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D9BF41800C34; Mon, 21 Jul 2025 05:59:37 +0000 (UTC) Received: from localhost.localdomain (unknown [10.72.112.190]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 1068B19560AD; Mon, 21 Jul 2025 05:59:34 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org Cc: Vladimir Sementsov-Ogievskiy , Lei Yang , Jason Wang Subject: [PULL 01/12] net/tap: drop too small packets Date: Mon, 21 Jul 2025 13:59:16 +0800 Message-ID: <20250721055927.75951-2-jasowang@redhat.com> In-Reply-To: <20250721055927.75951-1-jasowang@redhat.com> References: <20250721055927.75951-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.088, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Vladimir Sementsov-Ogievskiy Theoretically tap_read_packet() may return size less than s->host_vnet_hdr_len, and next, we'll work with negative size (in case of !s->using_vnet_hdr). Let's avoid it. Don't proceed with size == s->host_vnet_hdr_len as well in case of !s->using_vnet_hdr, it doesn't make sense. Tested-by: Lei Yang Signed-off-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Jason Wang --- net/tap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/tap.c b/net/tap.c index 23536c09b4..2a85936019 100644 --- a/net/tap.c +++ b/net/tap.c @@ -190,6 +190,11 @@ static void tap_send(void *opaque) break; } + if (s->host_vnet_hdr_len && size <= s->host_vnet_hdr_len) { + /* Invalid packet */ + break; + } + if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { buf += s->host_vnet_hdr_len; size -= s->host_vnet_hdr_len; -- 2.42.0