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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84290C433F5 for ; Tue, 8 Mar 2022 11:07:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346214AbiCHLIe (ORCPT ); Tue, 8 Mar 2022 06:08:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232487AbiCHLIc (ORCPT ); Tue, 8 Mar 2022 06:08:32 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DF107BCA3 for ; Tue, 8 Mar 2022 03:07:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646737654; 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=+pn0Gp2y98eJDXuA8y7deIirBU9DlxAAqoNDwwNiF2I=; b=HEWoJNxBjh1JFbB4T0BfJwHm0s79S9t41d+hJwXymIZVLA8QIx5ovnexcggdfhqpwj8zFv zcwh7eUzaaLMGVNFPjb9Bo7HgREhj/S9NfwZvGRWPhD0Rn2GvQ21ieoX3ULfHqaD0NZAA2 caVWETfiN1prRc0DDDdr4+yInC7Ok3M= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-634-PCJQEQZPNcGxco74m9ksvw-1; Tue, 08 Mar 2022 06:07:32 -0500 X-MC-Unique: PCJQEQZPNcGxco74m9ksvw-1 Received: by mail-ej1-f69.google.com with SMTP id k16-20020a17090632d000b006ae1cdb0f07so8500122ejk.16 for ; Tue, 08 Mar 2022 03:07:32 -0800 (PST) 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=+pn0Gp2y98eJDXuA8y7deIirBU9DlxAAqoNDwwNiF2I=; b=ROIx5UXao/x2sb1SxJXwWul79ZdoBcLwUsYG1wC0BuUK6PAox2/QHprN3zPQwDYeSF JLj0fNVBshbepl2LB8pVOLugmxlnITTTxojoE5j+nAAWqsbJKb1+g5pkrCLDcvX6feR9 bVRJL6s5mGbKeW8C1oqRA8puQAh2j69GgGlWTc8frMJW3ogbjrTFF/Vk73pO1MOtdGEt zjb6+UUXGpwqLhdceTRCCYv/xONSyGR6cjBTXZpsdNQbXQo8l74p8+w8Jvdn31zHXPs1 79bsdUU5f4J4Qjbv52rWjXq4REmg5cDgwIiM8B/Jaw9TCvRTZRETGBSBQFiWDd8UNIUd r2qg== X-Gm-Message-State: AOAM531bjYBbRGBRzykqLeoBs5YKCu2rvLBGm9Tzz+U+cT0Inq+23WYN 4TPeXnDtNIYFPdtqXu5TC/C/EU3HJXrtNPAKAiPi1tsinNEh1U6cPWGAVcjC6DwzHxxm5Xk1Dwu erumNKbqeIXa1ZLaTgzfMFbWa X-Received: by 2002:a17:907:6d1d:b0:6d8:9fc8:b1e1 with SMTP id sa29-20020a1709076d1d00b006d89fc8b1e1mr12410551ejc.466.1646737650940; Tue, 08 Mar 2022 03:07:30 -0800 (PST) X-Google-Smtp-Source: ABdhPJxesTWxnr9yva5EqLXO5ZOYMLukOGg2mvmb/yiXq/BaIek5yrIlr+WBV842eb0PxoGVnYMIYQ== X-Received: by 2002:a17:907:6d1d:b0:6d8:9fc8:b1e1 with SMTP id sa29-20020a1709076d1d00b006d89fc8b1e1mr12410534ejc.466.1646737650745; Tue, 08 Mar 2022 03:07:30 -0800 (PST) Received: from redhat.com ([2.55.138.228]) by smtp.gmail.com with ESMTPSA id e12-20020a056402190c00b0041615cd434csm5336300edz.60.2022.03.08.03.07.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 03:07:30 -0800 (PST) Date: Tue, 8 Mar 2022 06:07:26 -0500 From: "Michael S. Tsirkin" To: Lee Jones 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: <20220308060705-mutt-send-email-mst@kernel.org> 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: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 08, 2022 at 08:01:32AM +0000, Lee Jones wrote: > 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. yes let's do that pls. > -- > 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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 16E38C433FE for ; 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Tsirkin" To: Lee Jones Subject: Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Message-ID: <20220308060705-mutt-send-email-mst@kernel.org> References: <20220307191757.3177139-1-lee.jones@linaro.org> <20220307173439-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline 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" T24gVHVlLCBNYXIgMDgsIDIwMjIgYXQgMDg6MDE6MzJBTSArMDAwMCwgTGVlIEpvbmVzIHdyb3Rl Ogo+IE9uIE1vbiwgMDcgTWFyIDIwMjIsIE1pY2hhZWwgUy4gVHNpcmtpbiB3cm90ZToKPiAKPiA+ IE9uIE1vbiwgTWFyIDA3LCAyMDIyIGF0IDA3OjE3OjU3UE0gKzAwMDAsIExlZSBKb25lcyB3cm90 ZToKPiA+ID4gdmhvc3RfdnNvY2tfaGFuZGxlX3R4X2tpY2soKSBhbHJlYWR5IGhvbGRzIHRoZSBt dXRleCBkdXJpbmcgaXRzIGNhbGwKPiA+ID4gdG8gdmhvc3RfZ2V0X3ZxX2Rlc2MoKS4gIEFsbCB3 ZSBoYXZlIHRvIGRvIGhlcmUgaXMgdGFrZSB0aGUgc2FtZSBsb2NrCj4gPiA+IGR1cmluZyB2aXJ0 cXVldWUgY2xlYW4tdXAgYW5kIHdlIG1pdGlnYXRlIHRoZSByZXBvcnRlZCBpc3N1ZXMuCj4gPiAK PiA+IFBscyBqdXN0IGJhc2ljYWxseSBjb3B5IHRoZSBjb2RlIGNvbW1lbnQgaGVyZS4gdGhpcyBp cyBqdXN0IGNvbmZ1c2VzLgo+ID4gCj4gPiA+IEFsc28gV0FSTigpIGFzIGEgcHJlY2F1dGlvbmFy eSBtZWFzdXJlLiAgVGhlIHB1cnBvc2Ugb2YgdGhpcyBpcyB0bwo+ID4gPiBjYXB0dXJlIHBvc3Np YmxlIGZ1dHVyZSByYWNlIGNvbmRpdGlvbnMgd2hpY2ggbWF5IHBvcCB1cCBvdmVyIHRpbWUuCj4g PiA+IAo+ID4gPiBMaW5rOiBodHRwczovL3N5emthbGxlci5hcHBzcG90LmNvbS9idWc/ZXh0aWQ9 Mjc5NDMyZDMwZDgyNWU2M2JhMDAKPiA+IAo+ID4gQW5kIHRoaXMgaXMgYSBidWcgd2UgYWxyZWFk eSBmaXhlZCwgcmlnaHQ/Cj4gCj4gV2VsbCwgdGhpcyB3YXMgdGhlIGJ1ZyBJIHNldCBvdXQgdG8g Zml4Lgo+IAo+IEkgZGlkbid0IGtub3cgeW91ciBwYXRjaCB3YXMgaW4gZmxpZ2h0IGF0IHRoZSB0 aW1lLgo+IAo+ID4gPiBDYzogPHN0YWJsZUB2Z2VyLmtlcm5lbC5vcmc+Cj4gPiA+IFJlcG9ydGVk LWJ5OiBzeXpib3QrYWRjM2NiMzIzODU1ODZiZWM4NTlAc3l6a2FsbGVyLmFwcHNwb3RtYWlsLmNv bQo+ID4gCj4gPiBub3QgcmVhbGx5IGFwcGxpY2FibGUgYW55bW9yZSAuLi4KPiAKPiBJIGNhbiBy ZW1vdmUgdGhlc2UgaWYgaXQgaGVscHMuCgp5ZXMgbGV0J3MgZG8gdGhhdCBwbHMuCgo+IC0tIAo+ IExlZSBKb25lcyBb5p2O55C85pavXQo+IFByaW5jaXBhbCBUZWNobmljYWwgTGVhZCAtIERldmVs b3BlciBTZXJ2aWNlcwo+IExpbmFyby5vcmcg4pSCIE9wZW4gc291cmNlIHNvZnR3YXJlIGZvciBB cm0gU29Dcwo+IEZvbGxvdyBMaW5hcm86IEZhY2Vib29rIHwgVHdpdHRlciB8IEJsb2cKCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClZpcnR1YWxpemF0aW9u IG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpo dHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby92aXJ0dWFs aXphdGlvbg==