From nobody Mon Feb 9 11:17:18 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1745397856; cv=none; d=zohomail.com; s=zohoarc; b=TwjztA0ib9xno4B88rGHLj9r5szQLIU+TQBUETZ3cUM1bxHIT6nJ55VEFsPsaUYJjDzi2UCwqGEms2Kxqv2hN15CJFL2cukOve7Gw2jRvGx/tpTy+LN25Stlr91z7v0yOwGikLfRpzROTm0Vo6au5ON6aCf59Q0PPQaeXr9liVs= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1745397856; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=sRXJAQPaiLmZqT+mF6PCtOvMLYU1hzDAfxemuId4gd8=; b=f0GyinkZy9k/WgrDiemO5CcAPeTACHSK4ZYWWBrDxS9gOz98js20ZYoGiIFleLEuYqBXZu/iAXvmuN2SMZeuVu1LUV9fZxoXHYavm0kBiANbb+Rbs4IKfyRPcstUvHm2RhvWv4QouLDN6Wajg6DzAcMEH8YuZvjKdfyuyN6oThc= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1745397856125400.95646268365476; Wed, 23 Apr 2025 01:44:16 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.964181.1355041 (Exim 4.92) (envelope-from ) id 1u7Vi5-0007HR-J9; Wed, 23 Apr 2025 08:44:01 +0000 Received: by outflank-mailman (output) from mailman id 964181.1355041; Wed, 23 Apr 2025 08:44:01 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u7Vi5-0007HK-G9; Wed, 23 Apr 2025 08:44:01 +0000 Received: by outflank-mailman (input) for mailman id 964181; Wed, 23 Apr 2025 08:44:00 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u7Vi4-0007Gy-Fu for xen-devel@lists.xenproject.org; Wed, 23 Apr 2025 08:44:00 +0000 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [2a00:1450:4864:20::429]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 18c546f6-201f-11f0-9ffb-bf95429c2676; Wed, 23 Apr 2025 10:43:58 +0200 (CEST) Received: by mail-wr1-x429.google.com with SMTP id ffacd0b85a97d-3a064a3e143so839247f8f.3 for ; Wed, 23 Apr 2025 01:43:58 -0700 (PDT) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-39efa493230sm18286034f8f.64.2025.04.23.01.43.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Apr 2025 01:43:57 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 18c546f6-201f-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1745397837; x=1746002637; darn=lists.xenproject.org; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id:from:to:cc :subject:date:message-id:reply-to; bh=sRXJAQPaiLmZqT+mF6PCtOvMLYU1hzDAfxemuId4gd8=; b=RrAL0rYFMs/aMEGP4lthhInIvVwMLGcstibjkzeULQFdPzTtRfovp8SzasCwJGtXsn ARFzvUf/vN8s5UuWK6RkOUH+HbeXRVTFCzf4E/5dgurJrgmwG4LPVqL3vRymMAm+S5oH LoP7OonBlrhgbUt/XAfFc2s98AUA19uAMdKdUJyfARVChI1HTIMywy2jfEu58GIborTZ F4xJC7robBHpBpcd4IwBrC41FflnKtbUkSBb/iOTNOzQ/9bJaN3XLfyHb4XX+WLcuf+Q TK4QvUUiSZgkE+HiEnoNCxL6j7smCqE/92LmQr6K+wfcjYTidVyJ6L40fr+a61GcjgFS +gSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745397837; x=1746002637; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=sRXJAQPaiLmZqT+mF6PCtOvMLYU1hzDAfxemuId4gd8=; b=Omc/fgfgN3zLASwdLzWomMuqfJi6wuQcaFC15GB5Wxjirzu/zKiAt0mcVvJr5SiI0h HaNdKzXVFlBtUM8xbH4ULKUUMRCN5EE+hbL3Xs21XpKVp5cRvXKir+IWhaCC3KCF/Tyb FLmp6Ge80AxbejUAUdfOOb45YgbHHIuxIPHG4ZbAptE+FQZALiMTOjRj3uhURVx6JxW+ MCL/ii3QTJTylJRk+DJjXikat2NWlkjmvztK6uzFYQJK4IgvAUJmnOxRAhcVWgBj7s2X LSy7Giab51tJFfLhHr7SBSyUpn6vf/Qn32tne9gi5CGXS03tinU8aPjRvvxdmcHN1C4N bC+A== X-Gm-Message-State: AOJu0YwQIqvp7PkKVcA68Ajs81jjeoLffBwfeMCpkRCTzV/Qd4VFUhOJ RUwByA6lSYhHuFDlUs0ru1mECWMTMxGQ3DjVgB1yUdRjmEYs6tixystXqPy7USVRcR9hPJWxHw4 = X-Gm-Gg: ASbGncuJ0Hx6BpOKXA9mz+b7hgf+lPMsDHXRwjM9mFqVOnnhCNqmj9TI+id1IdolP8x qkPMM94lZFB6lyik+2cQP8wABxoHs+5iLRudIbe6FBgsgrZTEVE6MIuUp6q7i4rCWccen2DcF+P xMFYVqAMzU/pCHMYkNl8RRFQ/XkAn7OEga0VCngUhOlkmATnMDv8MiVirKvUxFZ5gOS9Cn4gMVa 9aOltAsMvqisw5ocfR964wv3jbO6yKM3A79RJynibiibfeod+BzsyR9SpwWTn4kwxn76o5HRtVx 3XAL210viSO90SIIvZ6PWeSLTE7I6Wl4d2azLAjfoW70hzP7Yq6ZePUpuruNBRiYmvI+U9BY5Bt IKKzWvIGnhcA6Mdcrx8xTIhEpGQ== X-Google-Smtp-Source: AGHT+IGrDWdbEn1bJF16CdwpXCotm0IS9q51faRT3Bus6600G8ZHXsCEUCRHBIjuw5k7x9vsfYBctg== X-Received: by 2002:a05:6000:2405:b0:39c:266c:136d with SMTP id ffacd0b85a97d-39efba2aa92mr14093802f8f.12.1745397837633; Wed, 23 Apr 2025 01:43:57 -0700 (PDT) Message-ID: <570ad3f2-7f3b-4579-a000-c85d27e8bf77@suse.com> Date: Wed, 23 Apr 2025 10:43:56 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Marek Marczykowski From: Jan Beulich Subject: [PATCH] x86: constrain sub-page access length in mmio_ro_emulated_write() Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) X-ZM-MESSAGEID: 1745397859594019100 Content-Type: text/plain; charset="utf-8" Without doing so we could trigger the ASSERT_UNREACHABLE() in subpage_mmio_write_emulate(). A comment there actually says this validation would already have been done ... Fixes: 8847d6e23f97 ("x86/mm: add API for marking only part of a MMIO page = read only") Signed-off-by: Jan Beulich --- Alternatively we could drop comment and assertion from subpage_mmio_write_emulate(). --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -5195,8 +5195,9 @@ int cf_check mmio_ro_emulated_write( return X86EMUL_UNHANDLEABLE; } =20 - subpage_mmio_write_emulate(mmio_ro_ctxt->mfn, PAGE_OFFSET(offset), - p_data, bytes); + if ( bytes <=3D 8 ) + subpage_mmio_write_emulate(mmio_ro_ctxt->mfn, PAGE_OFFSET(offset), + p_data, bytes); =20 return X86EMUL_OKAY; }