From owner-freebsd-bugs@FreeBSD.ORG Fri Apr 24 19:05:10 2015 Return-Path: Delivered-To: freebsd-bugs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 82C8CF26 for ; Fri, 24 Apr 2015 19:05:10 +0000 (UTC) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 528D1152E for ; Fri, 24 Apr 2015 19:05:10 +0000 (UTC) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.14.9/8.14.9) with ESMTP id t3OJ5AtJ003721 for ; Fri, 24 Apr 2015 19:05:10 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 199673] sysctl(8) suffers a multiplication overflow when formatting vm.vmtotal Date: Fri, 24 Apr 2015 19:05:10 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: 10.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: vmagerya@gmail.com X-Bugzilla-Status: New X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Apr 2015 19:05:10 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199673 Bug ID: 199673 Summary: sysctl(8) suffers a multiplication overflow when formatting vm.vmtotal Product: Base System Version: 10.0-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: vmagerya@gmail.com Created attachment 155955 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=155955&action=edit sysctl-overflow.diff Here's a part of 'sysctl vm.mvtotal' output on my 10.0/amd64 machine: % sysctl vm.vmtotal [...] Virtual Memory: (Total: 1654588K Active: 1536668K) [...] If on the other hand, when I try to retrieve the same data via sysctl(3), I get different total virtual memory: % cat >test.c <<'EOF' #include #include #include #include #include int main() { struct vmtotal vt = {0}; size_t vtlen = sizeof(vt); if (sysctlbyname("vm.vmtotal", &vt, &vtlen, NULL, 0) != 0) return -1; ssize_t pagesize = getpagesize()/1024; printf("vm.vmtotal.t_vm = %zd pages (%zd kB)\n", (ssize_t)vt.t_vm, pagesize*vt.t_vm); return 0; } 'EOF' % c99 test.c && ./a.out vm.vmtotal.t_vm = 1074154446 pages (4296617784 kB) As you can see, the actual data coming out of sysctl(3) is 4296617784K, not 1654588K as sysctl(8) says. This is because sysctl(8) has a multiplication overflow in the 'S_vmtotal' function [1] when the number of pages ('t_vm') is multiplied by the page size ('pageKilo'). I'm attaching a (completely untested) patch to fix this problem; apply this patch to 'sbin/sysctl/sysctl.c'. [1] http://svnweb.freebsd.org/base/head/sbin/sysctl/sysctl.c?revision=278654&view=markup#l530 -- You are receiving this mail because: You are the assignee for the bug.