From mboxrd@z Thu Jan 1 00:00:00 1970 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=unavailable 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 A83A6C433E0 for ; Fri, 22 Jan 2021 20:06:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A4D523AFC for ; Fri, 22 Jan 2021 20:06:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730565AbhAVUGl (ORCPT ); Fri, 22 Jan 2021 15:06:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:35832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728354AbhAVON2 (ORCPT ); Fri, 22 Jan 2021 09:13:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4C2F923A9B; Fri, 22 Jan 2021 14:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611324608; bh=Ohi3lbdYamlZv7/5kwTSRLQED6psUb4Pb71oq58o9pM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IrkeSevS5uRjzjvHlCFo5U/j5hNPVBWNbB1D0q+GKVdNCnupf4I/cn8JWXH7R6/SJ CkILEC8KPI+5TlGzyhUZuaZAMxZgO25FJ07uqr8Ep26RMiPWFH6GPIfHkNbp9fSvVy OHu4GKMmNPxLDgElcsxgto3SRRje+4qE2fpWQSWU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.4 14/31] NFS: nfs_igrab_and_active must first reference the superblock Date: Fri, 22 Jan 2021 15:08:28 +0100 Message-Id: <20210122135732.446757237@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135731.873346566@linuxfoundation.org> References: <20210122135731.873346566@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible.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 @@ -534,12 +534,14 @@ extern int nfs41_walk_client_list(struct 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)