diff options
| -rw-r--r-- | fs/nfs_common/nfslocalio.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c index dd715cdb6c04..85aa03a7b020 100644 --- a/fs/nfs_common/nfslocalio.c +++ b/fs/nfs_common/nfslocalio.c @@ -292,8 +292,22 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid, localio = nfs_to->nfsd_open_local_fh(net, uuid->dom, rpc_clnt, cred, nfs_fh, pnf, fmode); if (!IS_ERR(localio) && nfs_uuid_add_file(uuid, nfl) < 0) { - /* Delete the cached file when racing with nfs_uuid_put() */ + /* + * Delete the cached file when racing with nfs_uuid_put(). + * Since nfl->nfs_uuid was never published via + * rcu_assign_pointer(), nfs_close_local_fh() will early-return + * and cannot clean up after us. Drop the slot's file ref and + * its paired net ref, then drop the caller-owned nfsd_file ref + * (+1) and the entry-time nfsd_net ref carried via nf->nf_net, + * and return -ENXIO so the caller never dereferences the + * now-cleared localio. + */ + struct nfsd_file __rcu *tmp = + (struct nfsd_file __force __rcu *)localio; + nfs_to_nfsd_file_put_local(pnf); + nfs_to_nfsd_file_put_local(&tmp); + localio = ERR_PTR(-ENXIO); } nfs_to_nfsd_net_put(net); |