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 C24F215854A for ; Fri, 6 Sep 2024 08:43:49 +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=1725612232; cv=none; b=O/gzHpF39VgreA/yscn08k8pmyuux+2dZDuvvEoyTaoI6vwcngzEw1/SxtqtUvkQOy8oXEMEkbmY4XFtu6p1W+83rmFChQgc4clxBmi0303+OO3Ytb4UuNcvMgpMeZOQKmG8z+l2kHYQOIt/wwLjqiCxLgyBK1NzSOD/I6VS6uk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725612232; c=relaxed/simple; bh=sYAOHM0OcG0NaZIXeSEYiH/+ryFpU5Tt0KGgp831Ug8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: In-Reply-To:Content-Type:Content-Disposition; b=i7/eThrY3U4XPssmg8qzvEsWdx4xRYojAfVQT119m8WHHwYuX7hTs2IB1mgWdEh7BDe2//DoZzTkyfJCpmudbCY2Olugu0ZOhWL9JkhqTlOj5LzB4h/mdM3cJkwuwIZ6ueAYXhMAZnJpYhqGr3qZ3C36BZ2Ye47qVopaULZIKNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=HAFJO9n3; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="HAFJO9n3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1725612228; 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=IO25rrrQNWDfL7Bn6AqoZkvugHO7UKf+pbprMwvZuwI=; b=HAFJO9n30pN9VXIAKnLVWarDI+9ii00yw1Tm7SctZKfZ7cCfc98ofEfLAmIyj1sMBSRbz3 kxLojnI9A/xKGklAsoQrK9EYgiaIgxpcDN4JOTHW3rHyY03SK6YCb9LMsIMmvXdnudga6B iJlyfyKQrGeFGFMplqMP41JxU1ajctw= Received: from mail-lj1-f199.google.com (mail-lj1-f199.google.com [209.85.208.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-621-PAO2XogGNU2pj5w2hAGBmQ-1; Fri, 06 Sep 2024 04:43:45 -0400 X-MC-Unique: PAO2XogGNU2pj5w2hAGBmQ-1 Received: by mail-lj1-f199.google.com with SMTP id 38308e7fff4ca-2f3eda3d1cfso16842961fa.1 for ; Fri, 06 Sep 2024 01:43:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725612224; x=1726217024; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=IO25rrrQNWDfL7Bn6AqoZkvugHO7UKf+pbprMwvZuwI=; b=YKYDaPQd4rFHBxcR7V4i8QGtks97WqUe1trviZRYqWqGuRRBJ6wsQz3o15b7AUn8hE hHng6N1zMTa9zCpMULcNpvxCaqF+NbLsiiTTCoTcDE/Me71TIKPCrUFqmcSFqOnsAZEN UCBkkrSuugFpKfgLv68BYp6pBbaiFYPzqhElNvFY0bDnlgvIViRnF56EbsPxcAqUdiKU B03bWSlGWQqhnLulDdfjlCjg8zG9p1toUH15Jae4mwE1o3XSrOZURTiaUozFuKaFzEub yDZL/wABunncvRP5f0uBt85KmIT4kikCPHr5UqgSJlVkE08cgdxJZ6KnQ27fZlT5l3ID QJfA== X-Forwarded-Encrypted: i=1; AJvYcCVIzRMsVd4KQK7oxxMcu/l13BNS3A4250NJiT5aiH7Y/bd9TOc6Z4Iq6CBI99goZIGmSC4OKd9dmSD5kUAL7g==@lists.linux.dev X-Gm-Message-State: AOJu0YxCu9qOfGXdDoSlZsv5hdtiLgR7MfYqPPz/vkvHFJwDh/wCHPEm CbExhQF+TecDNtyPkD1sd6bWtbwX3Vw5nGHOEICGN2+uFNLLmkQlA3XBuZYaO2OpLlr8HcygHkC xYdulW4/COPTP5q3nRPD4sA53LXpEGytiauq2oGBnt5S0HViHm783ty7d63yl8BWv X-Received: by 2002:a05:651c:1991:b0:2ec:568e:336e with SMTP id 38308e7fff4ca-2f751eaee1bmr12706951fa.1.1725612223737; Fri, 06 Sep 2024 01:43:43 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGT+z1w/z6YN28OpYeQ2dCulE2Kp/kot3f3CSP7P9f6Mz64pmj479twCfW6YqxPhHrxWVHjkg== X-Received: by 2002:a05:651c:1991:b0:2ec:568e:336e with SMTP id 38308e7fff4ca-2f751eaee1bmr12706321fa.1.1725612222476; Fri, 06 Sep 2024 01:43:42 -0700 (PDT) Received: from redhat.com ([2a02:14f:1f8:6afa:d56e:f70d:1d1b:3f10]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42ca05c6340sm13175775e9.4.2024.09.06.01.43.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Sep 2024 01:43:41 -0700 (PDT) Date: Fri, 6 Sep 2024 04:43:29 -0400 From: "Michael S. Tsirkin" To: Xuan Zhuo Cc: netdev@vger.kernel.org, Jason Wang , Eugenio =?iso-8859-1?Q?P=E9rez?= , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , virtualization@lists.linux.dev, Si-Wei Liu , Darren Kenny Subject: Re: [PATCH net] virtio-net: fix overflow inside virtnet_rq_alloc Message-ID: <20240906044143-mutt-send-email-mst@kernel.org> References: <20240820071913.68004-1-xuanzhuo@linux.alibaba.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240820071913.68004-1-xuanzhuo@linux.alibaba.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Aug 20, 2024 at 03:19:13PM +0800, Xuan Zhuo wrote: > leads to regression on VM with the sysctl value of: > > - net.core.high_order_alloc_disable=1 > > which could see reliable crashes or scp failure (scp a file 100M in size > to VM): > > The issue is that the virtnet_rq_dma takes up 16 bytes at the beginning > of a new frag. When the frag size is larger than PAGE_SIZE, > everything is fine. However, if the frag is only one page and the > total size of the buffer and virtnet_rq_dma is larger than one page, an > overflow may occur. In this case, if an overflow is possible, I adjust > the buffer size. If net.core.high_order_alloc_disable=1, the maximum > buffer size is 4096 - 16. If net.core.high_order_alloc_disable=0, only > the first buffer of the frag is affected. > > Fixes: f9dac92ba908 ("virtio_ring: enable premapped mode whatever use_dma_api") > Reported-by: "Si-Wei Liu" > Closes: http://lore.kernel.org/all/8b20cc28-45a9-4643-8e87-ba164a540c0a@oracle.com > Signed-off-by: Xuan Zhuo Guys where are we going with this? We have a crasher right now, if this is not fixed ASAP I'd have to revert a ton of work Xuan Zhuo just did. > --- > drivers/net/virtio_net.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index c6af18948092..e5286a6da863 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -918,9 +918,6 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp) > void *buf, *head; > dma_addr_t addr; > > - if (unlikely(!skb_page_frag_refill(size, alloc_frag, gfp))) > - return NULL; > - > head = page_address(alloc_frag->page); > > dma = head; > @@ -2421,6 +2418,9 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, > len = SKB_DATA_ALIGN(len) + > SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > > + if (unlikely(!skb_page_frag_refill(len, &rq->alloc_frag, gfp))) > + return -ENOMEM; > + > buf = virtnet_rq_alloc(rq, len, gfp); > if (unlikely(!buf)) > return -ENOMEM; > @@ -2521,6 +2521,12 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, > */ > len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room); > > + if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp))) > + return -ENOMEM; > + > + if (!alloc_frag->offset && len + room + sizeof(struct virtnet_rq_dma) > alloc_frag->size) > + len -= sizeof(struct virtnet_rq_dma); > + > buf = virtnet_rq_alloc(rq, len + room, gfp); > if (unlikely(!buf)) > return -ENOMEM; > -- > 2.32.0.3.g01195cf9f