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 6D943C4332F for ; Mon, 13 Dec 2021 14:28:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239344AbhLMO2a (ORCPT ); Mon, 13 Dec 2021 09:28:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239310AbhLMO22 (ORCPT ); Mon, 13 Dec 2021 09:28:28 -0500 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90EFEC061574; Mon, 13 Dec 2021 06:28:27 -0800 (PST) Received: by mail-ed1-x529.google.com with SMTP id o20so53115960eds.10; Mon, 13 Dec 2021 06:28:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=L1YqcUf8tUArbOAJMXi15iOKQNwtOCLTu+LlsK480y4=; b=MZoL1XTnWw68iKuFmUQwDRPIHn+gdJEMTqBWsL7u+j2IalNHz/MEUcqVDOSbHnMCkQ N3ysq+hCStY6ZUoYzGVwH9RDSlNIXVTJ0WwFfbyGpKB2RpWWp8I+iCXMu/mnmaBBYrTA TRk7fxHXK51ogiDRDDLTIGy8RXlxIBatwDB8dRhxiwcYo3tYxcVmjcmYuVQbsWLbGrgO tOMigK+hQF0raDST9EJrP7s5oSGcEquqICpRF9VMKw4SbuGYvOu9kvCPcrxpWO85NzlD VCNaitRzyXuEmKX5rCC/r5W38O0YGswo8lZpcekHezC1D/4VKB4xaVYtRTxSbrom+Cj5 tPFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=L1YqcUf8tUArbOAJMXi15iOKQNwtOCLTu+LlsK480y4=; b=5HBmgwE9QSLJitzIB0CE9duQsSQZHlygYiPYFfcEihCw/9IzHartqTQ/3ow9U2jSSO 2F+NFKYDTVxu49g/8Zyu19dYrIYPa68oYtHzZQS1aStR01ClZgSaiFlmLOOGzDb2qKiH JcvD9sBoMIaiKC0o6ZRK/5OblykRmmgXUbxqMGD8kzdvctsUEluxe3rnnBjAI6mpfCqL 0eROvmAU0UTD9lbtxYQV1OJxxyY7Xoa5FN5KBDqZB1/ydWOQ3EOIyAfxxK0+MmynkRH9 PEWLyoKE0LormmV6qRCHh1HS1wQmU5Y6YI5/hmzcZJf3Z1DaABJQ/psG4hEIajQDyCqV h+1Q== X-Gm-Message-State: AOAM5319Ceb5xBzwjiFFd/NuIVY/rkeeWIzgmnvQritd2NIlAiXBJm+o ljTGDJSckRs1BIc1ZkA9LDM= X-Google-Smtp-Source: ABdhPJxXh/83cDzm4RIF5R6fORGy/0AjXS454rmeCqthFz8xFx6m9UKgAHY2/D8Mqw5pGskFZWSm0Q== X-Received: by 2002:a17:907:60d6:: with SMTP id hv22mr45291141ejc.503.1639405705648; Mon, 13 Dec 2021 06:28:25 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id m25sm6438972edj.80.2021.12.13.06.28.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Dec 2021 06:28:25 -0800 (PST) Sender: Paolo Bonzini Message-ID: Date: Mon, 13 Dec 2021 15:28:24 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH MANUALSEL 5.15 8/9] KVM: downgrade two BUG_ONs to WARN_ON_ONCE Content-Language: en-US To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: kvm@vger.kernel.org References: <20211213141944.352249-1-sashal@kernel.org> <20211213141944.352249-8-sashal@kernel.org> From: Paolo Bonzini In-Reply-To: <20211213141944.352249-8-sashal@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/21 15:19, Sasha Levin wrote: > From: Paolo Bonzini > > [ Upstream commit 5f25e71e311478f9bb0a8ef49e7d8b95316491d7 ] > > This is not an unrecoverable situation. Users of kvm_read_guest_offset_cached > and kvm_write_guest_offset_cached must expect the read/write to fail, and > therefore it is possible to just return early with an error value. > > Signed-off-by: Paolo Bonzini > Signed-off-by: Sasha Levin > --- > virt/kvm/kvm_main.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index ce1847bc898b2..c6bfd4e15d28a 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -3001,7 +3001,8 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, > int r; > gpa_t gpa = ghc->gpa + offset; > > - BUG_ON(len + offset > ghc->len); > + if (WARN_ON_ONCE(len + offset > ghc->len)) > + return -EINVAL; > > if (slots->generation != ghc->generation) { > if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) > @@ -3038,7 +3039,8 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, > int r; > gpa_t gpa = ghc->gpa + offset; > > - BUG_ON(len + offset > ghc->len); > + if (WARN_ON_ONCE(len + offset > ghc->len)) > + return -EINVAL; > > if (slots->generation != ghc->generation) { > if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) > Acked-by: Paolo Bonzini