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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 82256CDB47F for ; Thu, 25 Jun 2026 05:57:10 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1345248.1604158 (Exim 4.92) (envelope-from ) id 1wcd4o-0000DF-6i; Thu, 25 Jun 2026 05:56:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1345248.1604158; Thu, 25 Jun 2026 05:56:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1wcd4o-0000D7-0x; Thu, 25 Jun 2026 05:56:38 +0000 Received: by outflank-mailman (input) for mailman id 1345248; Thu, 25 Jun 2026 05:56:36 +0000 Received: from mx.expurgate.net ([195.190.135.10]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1wcd4m-0000D1-Kr for xen-devel@lists.xenproject.org; Thu, 25 Jun 2026 05:56:36 +0000 Received: from mx.expurgate.net (helo=localhost) by mx.expurgate.net with esmtp id 1wcd4j-004b7r-Jy for xen-devel@lists.xenproject.org; Thu, 25 Jun 2026 07:56:33 +0200 Received: from [10.42.69.6] (helo=localhost) by localhost with ESMTP (eXpurgate MTA 0.9.1) (envelope-from ) id 6a3cc305-bab6-0a2a0a5309dd-0a2a4506c706-26 for ; Thu, 25 Jun 2026 07:56:33 +0200 Received: from [209.85.128.44] (helo=mail-wm1-f44.google.com) by tlsNG-16d1c6.mxtls.expurgate.net with ESMTPS (eXpurgate 4.57.1) (envelope-from ) id 6a3cc311-08de-0a2a45060019-d155802cd433-3 for ; Thu, 25 Jun 2026 07:56:33 +0200 Received: by mail-wm1-f44.google.com with SMTP id 5b1f17b1804b1-49249072f03so10065435e9.0 for ; Wed, 24 Jun 2026 22:56:33 -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 5b1f17b1804b1-4926417f0c7sm44793225e9.14.2026.06.24.22.56.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Jun 2026 22:56:32 -0700 (PDT) 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" Authentication-Results: eu.smtp.expurgate.cloud; dkim=pass header.s=google header.d=suse.com header.i="@suse.com" header.h="Content-Transfer-Encoding:In-Reply-To:Autocrypt:From:Content-Language:References:Cc:To:Subject:User-Agent:MIME-Version:Date:Message-ID" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1782366993; x=1782971793; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=6oPpsWMV6uUB1sMYbM5+qpNnZgsoLiynBAJlgm9Lpik=; b=DkkjSoYk0s+COygHuKPr7YnW82IgYlSS9hf9vV80e9PgoeJRG+ZIyFKdD9wn36eSiL QFrIw2NUoll9zOc+tTLo9GTzsyBG7B7KPVQH9hyuDCAod5g95voqk1/ll0bEyOnSo2K5 R78dyDViMTYk6kuPk4E5mlZxc7OvaeEyIOOsIpGpkqdGAm6TCkglRy/Q9LfACAFix0YW oJ1MlkfQKSOSqY3Nze4PJLGCLjPWV2Ud6232jvI49HD2Qb2SwZoL3+uDRqNpqZ+HyVqu 1MYG4QYCyGlKQqHXOP1HKAAbSoE7SPYntTtywIEHIqXe+qcpLBOVfJqqD1WfDWm/vKiA 7TQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782366993; x=1782971793; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=6oPpsWMV6uUB1sMYbM5+qpNnZgsoLiynBAJlgm9Lpik=; b=ewal5cyI1zijSj1DNAnnkwelXSYRB0fEZYvL6E7UfoxXrsQBRC2asSMiKrZwMjVYSr XKXA7Y8TRm7Nr0kYze6zUa1d8VSf+Vh0EhBVf/xiFZMUDnsQHTgfZUwT5teexJ4WZ/qm BPdjHZ+Ei4LVKmMKAoqO8Vp/tLAM/GiDq+NHopNcJWuXIbKUIt4USRaZ7SCSwNcILMvD MmGAMeHWLK7PG4uporWiZDtMWV0djRttbLZ0zu2VzM3CvrZg2EKaHIZRF5b0zkzhm/cq +DWNbG89lk5NhzbHEtSYEdu2N3tnInzbIOTcIdcDjVXvXTHf/WBdcGNzVEe8urvpsyxS P7gQ== X-Forwarded-Encrypted: i=1; AFNElJ+dJaYsWdDFvHAFOYWpJL9ZgPS7X0Cq7pBrEz5fc34vbqQahc5vkkfAsdbBYeEWIx7EQbsZpjl+w0k=@lists.xenproject.org X-Gm-Message-State: AOJu0YwM0xa7YtLQJ/9JcDBzvFqlxzzce8OOz//ptEYRUAjj0UXARdYR DrmckWprv3i7pCHRPtel+7KY9prg+SBqO5/T8q8Kmqf4wKkuFW2C1kmvKpM+NO2pVw== X-Gm-Gg: AfdE7cm7s3yXr86W0WOwLd5aWFje/yi+zu8O4+3t5zHa1fZ9bQvDVMf38t/Pp3R2lOQ 0idUoE+ADwXJX+MCPHO0eBobcNf24oyW/D0HcWRhcRIKCBNepDYZf6FWqyMSsyBGSSIT+h7WUvu YPwTFdi/fFsroLooVKa2UyukXQgIYzmNCQJuj4UAOsWp10LvObDDzu6f7MoG+RTjdm6V5Ahc8zn LgbqXUhsVDJAPCWg06/+XjO+waEBb/T2IuB2SZNMkCgX5Jg+L/s1sE7+j4Ioz8auWmhNrB+GB7o eBFouwrC2TfLbBRV4SI4BsgRTjM/TQ+vai9W6IvBIOud0MFafyoF4oUnT22HxY41tfnmmpPdXTl /DoJ/U2k9fN9NCf/KzpYHLyP/iZlvdX55/75pgy7VjCVQHX+5EdrSVf+5VrsWKjhBwENZ2EVhv5 4ZRZEVREM8GWesimdYy30uxLxYwbmMlPrgV11wd4cpDsJFjdTkgQMeFWjl+lv4hhEWNN1TEGogo Kuq X-Received: by 2002:a05:600c:c4a5:b0:492:2e48:81e6 with SMTP id 5b1f17b1804b1-4926684a6b7mr11453825e9.4.1782366992788; Wed, 24 Jun 2026 22:56:32 -0700 (PDT) Message-ID: Date: Thu, 25 Jun 2026 07:56:31 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: New Defects reported by Coverity Scan for XenProject To: Jason Andryuk Cc: Juergen Gross , Julien Grall , "xen-devel@lists.xenproject.org" References: <6a3bce99e5494_767442bc3001679a440720@prd-scan-dashboard-0.mail> Content-Language: en-US From: Jan Beulich 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 In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-purgate-ID: tlsNG-16d1c6/1782366993-C573868D-5CB49EDE/0/0 X-purgate-type: clean X-purgate-size: 1935 On 24.06.2026 23:53, Jason Andryuk wrote: > On 2026-06-24 09:04, Jan Beulich wrote: >> On 24.06.2026 14:33, scan-admin@coverity.com wrote: >>> ** CID 1695359: Insecure data handling (INTEGER_OVERFLOW) >>> /tools/xenstored/domain.c: 601 in domain_tree_remove_sub() >>> >>> >>> _____________________________________________________________________________________________ >>> *** CID 1695359: Insecure data handling (INTEGER_OVERFLOW) >>> /tools/xenstored/domain.c: 601 in domain_tree_remove_sub() >>> 595 node_changed = true; >>> 596 } >>> 597 >>> 598 for (i = 1; i < node->hdr.num_perms; i++) { >>> 599 if (node->perms[i].id != domain->domid) >>> 600 continue; >>>>>> CID 1695359: Insecure data handling (INTEGER_OVERFLOW) >>>>>> "8UL * (node->hdr.num_perms - i - 1U)", which might have underflowed, is passed to "memmove(node->perms + i, node->perms + i + 1, 8UL * (node->hdr.num_perms - i - 1U))". [Note: The source code implementation of the function has been overridden by a builtin model.] >>> 601 memmove(node->perms + i, node->perms + i + 1, >>> 602 sizeof(*node->perms) * (node->hdr.num_perms - i - 1)); >> >> I'm struggling with this one: As i < node->hdr.num_perms, the last argument >> passed to memmove() can be 0, but I can't see potential for underflow. > > This gave me pause on my initial review. On the final iteration, > node->perms + i + 1 will point past the end of the allocation, To be precise, it may point _at_ the end of the allocation (i.e. immediately past the last element), and hence still not UB. > but as > you say the size would be 0. I originally considered suggesting a check > and then decided it was unnecessary because of the 0. If Coverity's wording is to be trusted, such a check also wouldn't have helped here because 0 still is "no underflow". Jan