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[86.27.177.88]) by smtp.gmail.com with ESMTPSA id bg42-20020a05600c3caa00b00380deeaae72sm1978124wmb.1.2022.03.08.00.01.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 00:01:35 -0800 (PST) Date: Tue, 8 Mar 2022 08:01:32 +0000 From: Lee Jones To: "Michael S. Tsirkin" Cc: jasowang@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, stable@vger.kernel.org, syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com Subject: Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Message-ID: References: <20220307191757.3177139-1-lee.jones@linaro.org> <20220307173439-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220307173439-mutt-send-email-mst@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 07 Mar 2022, Michael S. Tsirkin wrote: > On Mon, Mar 07, 2022 at 07:17:57PM +0000, Lee Jones wrote: > > vhost_vsock_handle_tx_kick() already holds the mutex during its call > > to vhost_get_vq_desc(). All we have to do here is take the same lock > > during virtqueue clean-up and we mitigate the reported issues. > > Pls just basically copy the code comment here. this is just confuses. > > > Also WARN() as a precautionary measure. The purpose of this is to > > capture possible future race conditions which may pop up over time. > > > > Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00 > > And this is a bug we already fixed, right? Well, this was the bug I set out to fix. I didn't know your patch was in flight at the time. > > Cc: > > Reported-by: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com > > not really applicable anymore ... I can remove these if it helps. -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog 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 smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 D0209C433F5 for ; Tue, 8 Mar 2022 08:01:42 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 627C540A99; Tue, 8 Mar 2022 08:01:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YuqJFsFkc96z; Tue, 8 Mar 2022 08:01:41 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp2.osuosl.org (Postfix) with ESMTPS id B04C440A8C; Tue, 8 Mar 2022 08:01:40 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 887F2C0012; Tue, 8 Mar 2022 08:01:40 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id BD21BC000B for ; Tue, 8 Mar 2022 08:01:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id A993460F19 for ; Tue, 8 Mar 2022 08:01:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp3.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=linaro.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id U_-sM9yFn8Yw for ; Tue, 8 Mar 2022 08:01:37 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by smtp3.osuosl.org (Postfix) with ESMTPS id 61B3D60E87 for ; Tue, 8 Mar 2022 08:01:37 +0000 (UTC) Received: by mail-wr1-x430.google.com with SMTP id h15so2727381wrc.6 for ; Tue, 08 Mar 2022 00:01:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=IucybA/BbH72cgwgMkENy2nc0cw2uppzQpsI3A+UQng=; b=n2kvax4T596zRbJNHl3pnQBK56Kh3dAHGIATboCR3y4jygN1ehcf5ApBgDCV5Vb3y2 SLWndLQ0RqQWcpJbKcyPuO4ztnaTn3WfZR+tAtBuAeiJ0Y4BNeMp+yu7V3xAAAEvQsfw vGDZbgQA8EuIXMQU+qtoE3wx/BO1VbroSviRdyIUievVZU8k63A/eymNH8QYO7RND78l 0P+hi35rqJI6VNdQR07pPSUOTsEeJ7ZspVOX8afsoJi3MTripFjC89dnGdmYHSVLZ1dl 3WbZw96mkjwI/2AQL/umBpbHA+/2eq+3Ehftz+AHUwt9F0eWyqjKCErDO6inxcJrERVt OwuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=IucybA/BbH72cgwgMkENy2nc0cw2uppzQpsI3A+UQng=; b=jg/3QAYqEU42XXJ+MjN30pLE3hnMg9SPw43/WAdAQsUD69DHOBt0joqH5G7hyQrVxM kAqlLzMuFeNPz5W2B/7TgF0C7m8v1VNzxTsEoNSujOHxqlTEFUIa7xNEj0SOdv6nY19G WhW0v72o2HfMyWcLURcL+1rw3+tp/xf6Pq5xxeYCTgQOXimcEcZCWTZhrh4g9hWtDQUL bWvQ5IDYW5Z/QuykJdLJU3F/K65DI8im0+auYvn0408I/REvNMtccWIUk3dgmt6rMvli ZJSfT1o+5YEnvaht98DU3HKAd97yWU3xUV0psIsNmV8fvz70TvWwn4245+4qfamY/FE6 cbLg== X-Gm-Message-State: AOAM533a+3pAyxTUwRy2dxuysw0yZNOth7HOzT84H9AMUkSlvz1VREDC ctuCVFUdv+OIFVzDOTR2PH9Vkg== X-Google-Smtp-Source: ABdhPJz+6S70Pvi8hGyqht0OJu08Ak+kz7cIlHduA+N2p+09HFTvirJzU5DqlyxwJQXndXnzxWy20w== X-Received: by 2002:adf:e7c5:0:b0:1f2:1a3:f1a0 with SMTP id e5-20020adfe7c5000000b001f201a3f1a0mr5098043wrn.21.1646726495571; Tue, 08 Mar 2022 00:01:35 -0800 (PST) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id bg42-20020a05600c3caa00b00380deeaae72sm1978124wmb.1.2022.03.08.00.01.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 00:01:35 -0800 (PST) Date: Tue, 8 Mar 2022 08:01:32 +0000 From: Lee Jones To: "Michael S. Tsirkin" Subject: Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Message-ID: References: <20220307191757.3177139-1-lee.jones@linaro.org> <20220307173439-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220307173439-mutt-send-email-mst@kernel.org> Cc: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, virtualization@lists.linux-foundation.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" T24gTW9uLCAwNyBNYXIgMjAyMiwgTWljaGFlbCBTLiBUc2lya2luIHdyb3RlOgoKPiBPbiBNb24s IE1hciAwNywgMjAyMiBhdCAwNzoxNzo1N1BNICswMDAwLCBMZWUgSm9uZXMgd3JvdGU6Cj4gPiB2 aG9zdF92c29ja19oYW5kbGVfdHhfa2ljaygpIGFscmVhZHkgaG9sZHMgdGhlIG11dGV4IGR1cmlu ZyBpdHMgY2FsbAo+ID4gdG8gdmhvc3RfZ2V0X3ZxX2Rlc2MoKS4gIEFsbCB3ZSBoYXZlIHRvIGRv IGhlcmUgaXMgdGFrZSB0aGUgc2FtZSBsb2NrCj4gPiBkdXJpbmcgdmlydHF1ZXVlIGNsZWFuLXVw IGFuZCB3ZSBtaXRpZ2F0ZSB0aGUgcmVwb3J0ZWQgaXNzdWVzLgo+IAo+IFBscyBqdXN0IGJhc2lj YWxseSBjb3B5IHRoZSBjb2RlIGNvbW1lbnQgaGVyZS4gdGhpcyBpcyBqdXN0IGNvbmZ1c2VzLgo+ IAo+ID4gQWxzbyBXQVJOKCkgYXMgYSBwcmVjYXV0aW9uYXJ5IG1lYXN1cmUuICBUaGUgcHVycG9z ZSBvZiB0aGlzIGlzIHRvCj4gPiBjYXB0dXJlIHBvc3NpYmxlIGZ1dHVyZSByYWNlIGNvbmRpdGlv bnMgd2hpY2ggbWF5IHBvcCB1cCBvdmVyIHRpbWUuCj4gPiAKPiA+IExpbms6IGh0dHBzOi8vc3l6 a2FsbGVyLmFwcHNwb3QuY29tL2J1Zz9leHRpZD0yNzk0MzJkMzBkODI1ZTYzYmEwMAo+IAo+IEFu ZCB0aGlzIGlzIGEgYnVnIHdlIGFscmVhZHkgZml4ZWQsIHJpZ2h0PwoKV2VsbCwgdGhpcyB3YXMg dGhlIGJ1ZyBJIHNldCBvdXQgdG8gZml4LgoKSSBkaWRuJ3Qga25vdyB5b3VyIHBhdGNoIHdhcyBp biBmbGlnaHQgYXQgdGhlIHRpbWUuCgo+ID4gQ2M6IDxzdGFibGVAdmdlci5rZXJuZWwub3JnPgo+ ID4gUmVwb3J0ZWQtYnk6IHN5emJvdCthZGMzY2IzMjM4NTU4NmJlYzg1OUBzeXprYWxsZXIuYXBw c3BvdG1haWwuY29tCj4gCj4gbm90IHJlYWxseSBhcHBsaWNhYmxlIGFueW1vcmUgLi4uCgpJIGNh biByZW1vdmUgdGhlc2UgaWYgaXQgaGVscHMuCgotLSAKTGVlIEpvbmVzIFvmnY7nkLzmlq9dClBy aW5jaXBhbCBUZWNobmljYWwgTGVhZCAtIERldmVsb3BlciBTZXJ2aWNlcwpMaW5hcm8ub3JnIOKU giBPcGVuIHNvdXJjZSBzb2Z0d2FyZSBmb3IgQXJtIFNvQ3MKRm9sbG93IExpbmFybzogRmFjZWJv b2sgfCBUd2l0dGVyIHwgQmxvZwpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fXwpWaXJ0dWFsaXphdGlvbiBtYWlsaW5nIGxpc3QKVmlydHVhbGl6YXRpb25AbGlz dHMubGludXgtZm91bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5saW51eGZvdW5kYXRpb24ub3Jn L21haWxtYW4vbGlzdGluZm8vdmlydHVhbGl6YXRpb24=