nfsd: fix potential UAF in nfsd4_cb_getattr_release
Once we drop the delegation reference, the fields embedded in it are no
longer safe to access. Do that last.
Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 19d3987..02d43f9 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3078,9 +3078,9 @@ nfsd4_cb_getattr_release(struct nfsd4_callback *cb)
struct nfs4_delegation *dp =
container_of(ncf, struct nfs4_delegation, dl_cb_fattr);
- nfs4_put_stid(&dp->dl_stid);
clear_bit(CB_GETATTR_BUSY, &ncf->ncf_cb_flags);
wake_up_bit(&ncf->ncf_cb_flags, CB_GETATTR_BUSY);
+ nfs4_put_stid(&dp->dl_stid);
}
static const struct nfsd4_callback_ops nfsd4_cb_recall_any_ops = {
