From patchwork Tue Jan 5 09:29:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 357435 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, 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 56361C43331 for ; Tue, 5 Jan 2021 09:30:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E78920756 for ; Tue, 5 Jan 2021 09:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727908AbhAEJat (ORCPT ); Tue, 5 Jan 2021 04:30:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:49288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728342AbhAEJ3i (ORCPT ); Tue, 5 Jan 2021 04:29:38 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E52FC22AAC; Tue, 5 Jan 2021 09:28:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609838934; bh=3kuHzY4yx1SVEHMeOsRR8JLpQJFo33DMO4NBlvtdluo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MSkO20aXSFrPV0oSi6csmQpI6p2wx4tRblv0NvX7WvwBphNkfOGdwjrlY2rxrVxYk whzNmVjxW68buaaKaqRUQ1RvpnOsfWfr/5lQeXQ395NeMtnmhmfwlnvrhdGaw9pnh3 0pJBIT5WhuRsqLJeBJJi6iFusrTIM116d1RgaPmc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Sasha Levin Subject: [PATCH 4.19 26/29] NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode Date: Tue, 5 Jan 2021 10:29:12 +0100 Message-Id: <20210105090821.928785763@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210105090818.518271884@linuxfoundation.org> References: <20210105090818.518271884@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 [ Upstream commit b6d49ecd1081740b6e632366428b960461f8158b ] When returning the layout in nfs4_evict_inode(), we need to ensure that the layout is actually done being freed before we can proceed to free the inode itself. Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4super.c | 2 +- fs/nfs/pnfs.c | 33 +++++++++++++++++++++++++++++++-- fs/nfs/pnfs.h | 5 +++++ 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c index 6fb7cb6b3f4b0..e7a10f5f54057 100644 --- a/fs/nfs/nfs4super.c +++ b/fs/nfs/nfs4super.c @@ -95,7 +95,7 @@ static void nfs4_evict_inode(struct inode *inode) nfs_inode_return_delegation_noreclaim(inode); /* Note that above delegreturn would trigger pnfs return-on-close */ pnfs_return_layout(inode); - pnfs_destroy_layout(NFS_I(inode)); + pnfs_destroy_layout_final(NFS_I(inode)); /* First call standard NFS clear_inode() code */ nfs_clear_inode(inode); } diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 2b9e139a29975..a253384a4710b 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -294,6 +294,7 @@ void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) { struct inode *inode; + unsigned long i_state; if (!lo) return; @@ -304,8 +305,12 @@ pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) if (!list_empty(&lo->plh_segs)) WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n"); pnfs_detach_layout_hdr(lo); + i_state = inode->i_state; spin_unlock(&inode->i_lock); pnfs_free_layout_hdr(lo); + /* Notify pnfs_destroy_layout_final() that we're done */ + if (i_state & (I_FREEING | I_CLEAR)) + wake_up_var(lo); } } @@ -713,8 +718,7 @@ pnfs_free_lseg_list(struct list_head *free_me) } } -void -pnfs_destroy_layout(struct nfs_inode *nfsi) +static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi) { struct pnfs_layout_hdr *lo; LIST_HEAD(tmp_list); @@ -732,9 +736,34 @@ pnfs_destroy_layout(struct nfs_inode *nfsi) pnfs_put_layout_hdr(lo); } else spin_unlock(&nfsi->vfs_inode.i_lock); + return lo; +} + +void pnfs_destroy_layout(struct nfs_inode *nfsi) +{ + __pnfs_destroy_layout(nfsi); } EXPORT_SYMBOL_GPL(pnfs_destroy_layout); +static bool pnfs_layout_removed(struct nfs_inode *nfsi, + struct pnfs_layout_hdr *lo) +{ + bool ret; + + spin_lock(&nfsi->vfs_inode.i_lock); + ret = nfsi->layout != lo; + spin_unlock(&nfsi->vfs_inode.i_lock); + return ret; +} + +void pnfs_destroy_layout_final(struct nfs_inode *nfsi) +{ + struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi); + + if (lo) + wait_var_event(lo, pnfs_layout_removed(nfsi, lo)); +} + static bool pnfs_layout_add_bulk_destroy_list(struct inode *inode, struct list_head *layout_list) diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index 3ba44819a88ae..80fafa29e567a 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -254,6 +254,7 @@ struct pnfs_layout_segment *pnfs_layout_process(struct nfs4_layoutget *lgp); void pnfs_layoutget_free(struct nfs4_layoutget *lgp); void pnfs_free_lseg_list(struct list_head *tmp_list); void pnfs_destroy_layout(struct nfs_inode *); +void pnfs_destroy_layout_final(struct nfs_inode *); void pnfs_destroy_all_layouts(struct nfs_client *); int pnfs_destroy_layouts_byfsid(struct nfs_client *clp, struct nfs_fsid *fsid, @@ -645,6 +646,10 @@ static inline void pnfs_destroy_layout(struct nfs_inode *nfsi) { } +static inline void pnfs_destroy_layout_final(struct nfs_inode *nfsi) +{ +} + static inline struct pnfs_layout_segment * pnfs_get_lseg(struct pnfs_layout_segment *lseg) {