From patchwork Mon Jan 18 11:34:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 366824 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 CA454C43332 for ; Mon, 18 Jan 2021 19:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99B1022CA2 for ; Mon, 18 Jan 2021 19:27:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437322AbhART07 (ORCPT ); Mon, 18 Jan 2021 14:26:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:34100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390432AbhARLiL (ORCPT ); Mon, 18 Jan 2021 06:38:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3BF2C221EC; Mon, 18 Jan 2021 11:36:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610969802; bh=psplj7E6pbRF0VvFZdW6Qy+OBViV4uIQvI+KMFyV4bI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x0Uzzvj+6HGRU5dcm3b7uKe7DwuzhBLXg8zWh/i1pwaUu7/eWnO9fUv8Kxl3WZ6uG WFMue3X5tdLRej3GTVsdqj02U5NQJrNIY6hbQL7lW1yT7JvK0r/3UtDvfJx+FW/4Fr Fi9U3fzgQZwUG7eKPeZp0/q4Otf97/qNPXmmtufg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.19 32/43] NFS: nfs_igrab_and_active must first reference the superblock Date: Mon, 18 Jan 2021 12:34:55 +0100 Message-Id: <20210118113336.502926083@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210118113334.966227881@linuxfoundation.org> References: <20210118113334.966227881@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 @@ -575,12 +575,14 @@ 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)