From patchwork Fri Jul 12 18:42:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: patricia.domingues@canonical.com X-Patchwork-Id: 1960005 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=185.125.189.65; helo=lists.ubuntu.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=patchwork.ozlabs.org) Received: from lists.ubuntu.com (lists.ubuntu.com [185.125.189.65]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4WLL7K5n81z1xqj for ; Sat, 13 Jul 2024 04:42:37 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=lists.ubuntu.com) by lists.ubuntu.com with esmtp (Exim 4.86_2) (envelope-from ) id 1sSLDs-0004CS-Es; Fri, 12 Jul 2024 18:42:24 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by lists.ubuntu.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1sSLDq-0004CE-89 for kernel-team@lists.ubuntu.com; Fri, 12 Jul 2024 18:42:22 +0000 Received: from localhost.localdomain (1.general.patriciasd.us.vpn [10.172.64.192]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id DAB513F266 for ; Fri, 12 Jul 2024 18:42:19 +0000 (UTC) From: patricia.domingues@canonical.com To: kernel-team@lists.ubuntu.com Subject: [SRU][N][PATCH 0/1] nfsd: initialise nfsd_info.mutex early (LP: 2070358) Date: Fri, 12 Jul 2024 15:42:13 -0300 Message-Id: <20240712184214.251614-1-patricia.domingues@canonical.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" BugLink: https://bugs.launchpad.net/bugs/2070358 SRU Justification: [Impact] * When the sosreport command is executed, a kernel OOPS happens and the system is crashing, depending on the configuration (but default) the system/LPAR is rebooting. [Fix] * e0011bca603c101f2a3c007bdb77f7006fa78fb1 e0011bca603c "nfsd: initialise nfsd_info.mutex early" [Test Case] * Have a Ubuntu Server 24.04 LTS installation on ppc64el. * one option is only running sosreport on the system - and the crash is seen when the sosreport is starting to capture dump * second option (without sosreport) is: * CONFIG_NFSD=m (or y) must be set * mount nfsd if not already, using "$ mount -t nfsd nfsd /proc/fs/nfsd" command * The kernel oops will happen and the logs will show: ... BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc0000000016ff114 Oops: Kernel access of bad area, sig: 11 [#1] ... * On a system with that kernel that incl. the above patch no oops will occur and the sosreport command will execute normally. [Regression Potential] * There is a certain risk of a regression, with any code modification, and here because the mutex handling in nfsd is modified. * But the changes are pretty traceable. * On top the commit is already upstream reviewed and accepted. * The modifications were done by the NFSD maintainer and also tested by IBM. [Other] * The fix/commit got upstream accepted with kernel v6.10-rc7, hence Oracular is not affected. NeilBrown (1): nfsd: initialise nfsd_info.mutex early. fs/nfsd/nfsctl.c | 2 ++ fs/nfsd/nfssvc.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) Acked-by: Kevin Becker Acked-by: Manuel Diewald