From patchwork Fri Jan 22 14:10:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 369354 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EE2EC43219 for ; Fri, 22 Jan 2021 19:59:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48CF623AFC for ; Fri, 22 Jan 2021 19:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730760AbhAVT6p (ORCPT ); Fri, 22 Jan 2021 14:58:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:34412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbhAVOOD (ORCPT ); Fri, 22 Jan 2021 09:14:03 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4452523A5F; Fri, 22 Jan 2021 14:11:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611324664; bh=9q3kSDHOt1IVp/diBP4F39WtWudxppLFmPDFRhZz48Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TD2roMyYaT/78A5/ABwPEBd9qE4bSG4b4s9APMuUF6BgB2rEb6GkjQmvvo93Q9+ZW gMadDTcxLdpFWQ3l0jocGmn1OIKhGQyAmEmhziBsCB4yJ/BUFoMlUtBNPeYfNascYV YAV/n7Vt970wu5tk7+UYUhLc3+bc1MTwPBvUfC9Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.9 17/35] NFS: nfs_igrab_and_active must first reference the superblock Date: Fri, 22 Jan 2021 15:10:19 +0100 Message-Id: <20210122135733.017925650@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135732.357969201@linuxfoundation.org> References: <20210122135732.357969201@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Trond Myklebust commit 896567ee7f17a8a736cda8a28cc987228410a2ac upstream. Before referencing the inode, we must ensure that the superblock can be referenced. Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible. Fixes: ea7c38fef0b7 ("NFSv4: Ensure we reference the inode for return-on-close in delegreturn") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/internal.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -572,12 +572,14 @@ extern int nfs4_test_session_trunk(struc static inline struct inode *nfs_igrab_and_active(struct inode *inode) { - inode = igrab(inode); - if (inode != NULL && !nfs_sb_active(inode->i_sb)) { - iput(inode); - inode = NULL; + struct super_block *sb = inode->i_sb; + + if (sb && nfs_sb_active(sb)) { + if (igrab(inode)) + return inode; + nfs_sb_deactive(sb); } - return inode; + return NULL; } static inline void nfs_iput_and_deactive(struct inode *inode)