From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Sasha Levin Subject: [PATCH 4.19 092/110] NFSv4: Fix an Oops during delegation callbacks Date: Thu, 29 Nov 2018 15:13:03 +0100 Message-Id: <20181129135924.971468147@linuxfoundation.org> In-Reply-To: <20181129135921.231283053@linuxfoundation.org> References: <20181129135921.231283053@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit e39d8a186ed002854196668cb7562ffdfbc6d379 ] If the server sends a CB_GETATTR or a CB_RECALL while the filesystem is being unmounted, then we can Oops when releasing the inode in nfs4_callback_getattr() and nfs4_callback_recall(). Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/callback_proc.c | 4 ++-- fs/nfs/delegation.c | 11 +++++++++-- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index fa515d5ea5ba..7b861bbc0b43 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -66,7 +66,7 @@ __be32 nfs4_callback_getattr(void *argp, void *resp, out_iput: rcu_read_unlock(); trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status)); - iput(inode); + nfs_iput_and_deactive(inode); out: dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status)); return res->status; @@ -108,7 +108,7 @@ __be32 nfs4_callback_recall(void *argp, void *resp, } trace_nfs4_cb_recall(cps->clp, &args->fh, inode, &args->stateid, -ntohl(res)); - iput(inode); + nfs_iput_and_deactive(inode); out: dprintk("%s: exit with status = %d\n", __func__, ntohl(res)); return res; diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index f033f3a69a3b..75fe92eaa681 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -849,16 +849,23 @@ nfs_delegation_find_inode_server(struct nfs_server *server, const struct nfs_fh *fhandle) { struct nfs_delegation *delegation; - struct inode *res = NULL; + struct inode *freeme, *res = NULL; list_for_each_entry_rcu(delegation, &server->delegations, super_list) { spin_lock(&delegation->lock); if (delegation->inode != NULL && nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { - res = igrab(delegation->inode); + freeme = igrab(delegation->inode); + if (freeme && nfs_sb_active(freeme->i_sb)) + res = freeme; spin_unlock(&delegation->lock); if (res != NULL) return res; + if (freeme) { + rcu_read_unlock(); + iput(freeme); + rcu_read_lock(); + } return ERR_PTR(-EAGAIN); } spin_unlock(&delegation->lock); -- 2.17.1