From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 873DA3D5C07 for ; Thu, 21 May 2026 13:09:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779368985; cv=none; b=IuM4XFncWs/S2uhZW1KHUTrwY6Tg10fEW4qvSBNKw6u+7ZQj7GW0FZD5D+b5m8dneSveVl9QRVH5xSM9xGc3NhfRFuI5xCKxPl/WahvjmQCTP6uEVOBg3unrLxwjxiVnMGeME0OR+BnDtuta77GEPM6Kl9/mncU4uRkgGu0MHSA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779368985; c=relaxed/simple; bh=Jdm389GpaXuX2GWxlZhF6BpB83Vj3ksApFOhdPl2pZE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QCJMyuX1JWfoxUaep9Cr6KnoDo/f+SrTCTykGJgISpWwWfXYgGW7K2AL5SaLJmEd2OVZA7bxMuuey0qRigsXta1V2VH3QuLXTbhyvN4U3np+Vi/3yYa2RwAhWJn2pAHhXYJ0wxtZ4g6n/ZJ3xTK41SlSRcVrsyt3I4QlDasQONo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=V9VLScIj; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=gzUwknpy; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V9VLScIj"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="gzUwknpy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779368983; 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: in-reply-to:in-reply-to:references:references; bh=E1vW/XPFrOLYW0lggR7O8cskrXPHeM9SnYmkXYtZE2U=; b=V9VLScIjN+NhBKis4WUCTC2eyMjIRWjSwj2roLaAjHk8+GhLBsQy0RF1x7wi0vjDhb/apA 78TIbboWCWPAs0V37GtcSQoagELJTvQbNi1bLCHuBQNUpUz1u8RZpASjjpP6AidYZL9Zku RN8P/o4o1OuzVIPg05g9S56TYHuUFvQ= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-527-op--vcQtNd-M1cwAZEEN3w-1; Thu, 21 May 2026 09:09:41 -0400 X-MC-Unique: op--vcQtNd-M1cwAZEEN3w-1 X-Mimecast-MFC-AGG-ID: op--vcQtNd-M1cwAZEEN3w_1779368980 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-44bf1ac8893so4814561f8f.0 for ; Thu, 21 May 2026 06:09:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1779368979; x=1779973779; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=E1vW/XPFrOLYW0lggR7O8cskrXPHeM9SnYmkXYtZE2U=; b=gzUwknpykZJdMmq0ET5kHWWnIm59z8iScuw46XJl9HO4MtMct0S31JS9VQIqQS2Qmt qBI8bstnFhn27TxXDNzbtmsdowmCgKD/zzRC1Q4GtV3i7YFEWUyPcdp0V9CyN0tAu3lY rIXs7R3AKxDLQ7tw+s1Cm79+5P8EJ2WFsD3QGV2AMlxnkNVTV9hM233SYz0LvOgfxn8X kE8NdwFXAeyknjLtTifPCUm8ixQI578I4ZOsjrifkaf704+49owwj15NJRm5CdiuAcL8 efD6eBJ65vXfLmHZAIZ4zgN/Utp5GvP2yeryupHCCarB9JLxDysDCkFq8yg0GMo4ltfy f6QQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779368979; x=1779973779; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=E1vW/XPFrOLYW0lggR7O8cskrXPHeM9SnYmkXYtZE2U=; b=DHU503Y/JLGxuiTzQ1QsHZOrhlI8rgktBA0+zMk/4QnzuZpbeTGyp7E8QRmJRTyLaz eOq8V3YQiX84OJZU2DEwxdtWi/h4idKCaUDoKHSgG//qxzKzz4hIrG/8LyeuthTyjtGN p5bqcKl7+qAt2dZ6unm/SPQ8cf2bAVUW2bAqm5yBm7aADL5bBLg0JvEy9uLGEINdfOZv gylT9LU+VC3bwJ9zm81JnvcQKrgkvH+qHOcGHS+0ftQbTPDQpxKvgdVOUX1GPSHCkVjk pTpnVou4csizA8d+rVXyDWnfTwJO0m0NWDnRcJ8073IoDPJtlxsKOrPff+9bFv3kffQv bVUQ== X-Gm-Message-State: AOJu0Yzmu7fsMRzguTM6G9gwJ36pDLZ+fMYSBFyPdrEi2I2gQxglbyR9 YzDR+ZesgYHiXavjVZYsO/9EsqHtefDZgFDHj0JmDUf1BesanoMDv3KOjRzUtMSckcWab+fFBop DjrwAASmgIL1k+QQsOLIDLMLeKm3F2cHJEF8pBHVz2/n5Ruo0D7R+1qHqqQ== X-Gm-Gg: Acq92OGQSgoSdktz4dNcgYmfG5WPIA2mFWHrM6+Mkrjwtz409Cvwt+7d9NLas/jp41P 1irWBT+fmdvYm51bMRToqiIkJosReyKCsYP1VTUBvR3czqhDfBf1FCOSaxx3mjWgW7Out4d9Kzw EHHJWCFqravqGI/WxlUokYnfj7r3sPjYxA8A3D6yuzRlZEW6R/j2U7/0G4Ep97//B9MYon6bhhA mS4H7RgnO26LlavfzYXgyHIqq89qnnW5ZVlXZ2V4vwrHZQLnA1McXaR03RlihhducbKtQJtC0Hk GYnnrvwZzq5fNEsG9XILP5yRqnb69U3ZeXJ031fn0OTe9t6sSRm7C2cR87AWmbX1iWwM9U0asAU CpIlGVs+2lcvQUdIwnDIGXYMgPoH7tPdkjkvVwZlVYdU= X-Received: by 2002:a05:600c:a15:b0:490:3cef:bd90 with SMTP id 5b1f17b1804b1-4903cefbe6emr23446895e9.26.1779368979414; Thu, 21 May 2026 06:09:39 -0700 (PDT) X-Received: by 2002:a05:600c:a15:b0:490:3cef:bd90 with SMTP id 5b1f17b1804b1-4903cefbe6emr23445975e9.26.1779368978717; Thu, 21 May 2026 06:09:38 -0700 (PDT) Received: from redhat.com (IGLD-80-230-25-45.inter.net.il. [80.230.25.45]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49035edd7cfsm15236405e9.27.2026.05.21.06.09.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 May 2026 06:09:38 -0700 (PDT) Date: Thu, 21 May 2026 09:09:33 -0400 From: "Michael S. Tsirkin" To: Stefano Garzarella Cc: netdev@vger.kernel.org, Xuan Zhuo , Simon Horman , virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Jakub Kicinski , Eugenio =?iso-8859-1?Q?P=E9rez?= , Paolo Abeni , "David S. Miller" , Jason Wang , Stefan Hajnoczi , Eric Dumazet , stable@vger.kernel.org Subject: Re: [PATCH net] vsock/virtio: fix skb overhead overflow on 32-bit builds Message-ID: <20260521090927-mutt-send-email-mst@kernel.org> References: <20260521124732.125771-1-sgarzare@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260521124732.125771-1-sgarzare@redhat.com> On Thu, May 21, 2026 at 02:47:32PM +0200, Stefano Garzarella wrote: > From: Stefano Garzarella > > On 32-bit architectures, both skb_queue_len() and SKB_TRUESIZE(0) evaluate > to 32-bit values. The multiplication can overflow before being assigned to > the u64 skb_overhead variable, making the skb overhead check ineffective. > > Cast skb_queue_len() to u64 so the multiplication is always performed in > 64-bit arithmetic. > > This issue was reported by Sashiko while reviewing another patch. > > Fixes: 059b7dbd20a6 ("vsock/virtio: fix potential unbounded skb queue") > Closes: https://sashiko.dev/#/patchset/20260518090656.134588-1-sgarzare%40redhat.com > Cc: stable@vger.kernel.org > Signed-off-by: Stefano Garzarella Acked-by: Michael S. Tsirkin > --- > net/vmw_vsock/virtio_transport_common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c > index df3b418e0392..71198bf23fc4 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -417,7 +417,7 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, > static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, > u32 len) > { > - u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0); > + u64 skb_overhead = ((u64)skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0); > > /* Allow at most buf_alloc * 2 total budget (payload + overhead), > * similar to how SO_RCVBUF is doubled to reserve space for sk_buff > -- > 2.54.0