From owner-freebsd-ppc@freebsd.org Tue Feb 5 18:52:41 2019 Return-Path: Delivered-To: freebsd-ppc@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3D30814C57E7 for ; Tue, 5 Feb 2019 18:52:41 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id C2C118AA2F for ; Tue, 5 Feb 2019 18:52:40 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 7BEDF14C57E5; Tue, 5 Feb 2019 18:52:40 +0000 (UTC) Delivered-To: ppc@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 67F6114C57E3 for ; Tue, 5 Feb 2019 18:52:40 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id F05CB8AA2B for ; Tue, 5 Feb 2019 18:52:39 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) 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 mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 0744312B47 for ; Tue, 5 Feb 2019 18:52:39 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x15Iqcl5060077 for ; Tue, 5 Feb 2019 18:52:38 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x15Iqc9a060074 for ppc@FreeBSD.org; Tue, 5 Feb 2019 18:52:38 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: ppc@FreeBSD.org Subject: [Bug 233377] [PowerPC64] Panic during high disk I/O activity Date: Tue, 05 Feb 2019 18:52:38 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: markj@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: ppc@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-ppc@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Porting FreeBSD to the PowerPC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Feb 2019 18:52:41 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D233377 --- Comment #12 from Mark Johnston --- (In reply to Leandro Lupori from comment #11) Prior to rXXXXXX, zone_alloc_bucket() did: max =3D MIN(bucket->ub_entries, zone->uz_count); bucket->ub_cnt =3D zone->uz_import(zone->uz_arg, bucket->ub_bucket, max, domain, flags); However, the zone lock is not held at this point, so uz_count may change. = In particular, since MIN is a macro that evaluates its arguments twice, I beli= eve it's possible for max to end up being larger than bucket->ub_entries, which would result in a use-after-free. r343026 fixed this problem as part of some refactoring, so that might expla= in why you don't see it anymore. --=20 You are receiving this mail because: You are the assignee for the bug.=