Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1rAcY8-007R9h-Et for pgsql-hackers@arkaria.postgresql.org; Tue, 05 Dec 2023 21:01:48 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1rAcY6-00668r-VC for pgsql-hackers@arkaria.postgresql.org; Tue, 05 Dec 2023 21:01:46 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1rAcY6-00668j-Iq for pgsql-hackers@lists.postgresql.org; Tue, 05 Dec 2023 21:01:46 +0000 Received: from mail-il1-x12d.google.com ([2607:f8b0:4864:20::12d]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1rAcY4-008yX1-20 for pgsql-hackers@postgresql.org; Tue, 05 Dec 2023 21:01:45 +0000 Received: by mail-il1-x12d.google.com with SMTP id e9e14a558f8ab-35aa6107e9fso25436915ab.0 for ; Tue, 05 Dec 2023 13:01:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701810103; x=1702414903; darn=postgresql.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=izqX8punjxJfAvHZLaDX9L260bZrQRRuiaS9iORX3CY=; b=OYs+zaQFLXOPt9Sm2EiPem5PtltbUUCOcVMfn3zZOpGtNJMoap5BuvIXg2yt8FhsRY 722Rm/cy3EeuhxdD/y5P1shux0CnqTb7hlyLZ5rkfPK6SEYGVhzhMsyCVIBjKriIki4S NNwNdvhC5QhTqdNX/3c2UxDxbvf5+CagMORZy8o67MZpnbAHSvPAEYBZdHdKwh6JbolR oOKPSRpgT8+WFFqd8yP3iiaCsdYOIwBDqxaUJBNZRPv9B8JvPb015esELZn8KCymJv7y +d8BUlLmyj7fhcOK85q/pbwsSLXqri9MSgraT++F2RB2hkLoj8Nx7ylIAJHG1dOcQNXs UQOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701810103; x=1702414903; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=izqX8punjxJfAvHZLaDX9L260bZrQRRuiaS9iORX3CY=; b=LPdwhJNF/pHXKjjx/GuuJaXcfj3sev+sjQzwgR7CIjMcD8N9zzX5+SKDXCBYx/ohAo GL5bn7F577UiCbTDFPb2NSsMwLtrAQp0xrKNYFx02sczmNCGLsO9+2RSSbQmWV42Ims0 RISAfdDFeCzk9mpblpGu5LZPeqEEOEysbGzglGYJhFG61Qt74s4ygA6U2EjmJxKmWC2C vlaG2eKzC44Zj5HjyzhTDIsw7FfBGWNwvtVQCjG8tWep9rKFaHjDXuSYFPb27PJaZOs7 fo1XBUs7Jshf0woLAMNCSPcmB0QiTo14HrZdRZBQMLXc9iS4OG+4BWiFNMBYJgjRaeeu dTVw== X-Gm-Message-State: AOJu0Yxv3C69GtOyqpEElAbrMgu1NmKAv0+4QBxgc7XPqn3kd25PWsGc BQabHnG00QcRCp4nVnEfoYk= X-Google-Smtp-Source: AGHT+IGWdYPnP3RMmWs4Va83Clcb9TazWj/yZHcZwcHRJI3L38Zq6Oai/FFJgXAOyo/uDXhPsAxruQ== X-Received: by 2002:a92:6811:0:b0:35c:aeec:93fd with SMTP id d17-20020a926811000000b0035caeec93fdmr6755883ilc.5.1701810103262; Tue, 05 Dec 2023 13:01:43 -0800 (PST) Received: from nathanxps13 (162-195-168-172.lightspeed.stlsmo.sbcglobal.net. [162.195.168.172]) by smtp.gmail.com with ESMTPSA id t17-20020a92c0d1000000b0035d65093154sm814331ilf.70.2023.12.05.13.01.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Dec 2023 13:01:42 -0800 (PST) Date: Tue, 5 Dec 2023 15:01:41 -0600 From: Nathan Bossart To: Robert Haas Cc: Thomas Munro , pgsql-hackers Subject: Re: UBSan pointer overflow in xlogreader.c Message-ID: <20231205210141.GA2762421@nathanxps13> References: <20231205180402.GB2757816@nathanxps13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Tue, Dec 05, 2023 at 03:48:33PM -0500, Robert Haas wrote: > The patch LGTM, too. Thanks for investigating and writing the code. > The part about how the reserved kernel memory prevents the bug from > appearing on 32-bit systems but not 64-bit systems running in 32-bit > mode is pretty interesting -- I don't want to think about how long it > would have taken me to figure that out. +1 -- Nathan Bossart Amazon Web Services: https://aws.amazon.com