nfs4: start callback_ident at idr 1

commit c68a027c05709330fe5b2f50c50d5fa02124b5d8 upstream.

If clp->cl_cb_ident is zero, then nfs_cb_idr_remove_locked() skips removing
it when the nfs_client is freed.  A decoding or server bug can then find
and try to put that first nfs_client which would lead to a crash.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: d687031265 ("nfs4client: convert to idr_alloc()")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Benjamin Coddington
2015-11-20 09:56:20 -05:00
committed by Greg Kroah-Hartman
parent ef29913621
commit 308b77ea2d
+1 -1
View File
@@ -32,7 +32,7 @@ static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
return ret;
idr_preload(GFP_KERNEL);
spin_lock(&nn->nfs_client_lock);
ret = idr_alloc(&nn->cb_ident_idr, clp, 0, 0, GFP_NOWAIT);
ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
if (ret >= 0)
clp->cl_cb_ident = ret;
spin_unlock(&nn->nfs_client_lock);