From 5d63944f8206a80636ae8cb4b9107d3b49f43d37 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 13 Feb 2020 14:51:07 -0500 Subject: [PATCH] NFSv4: Ensure the delegation cred is pinned when we call delegreturn Ensure we don't release the delegation cred during the call to nfs4_proc_delegreturn(). Fixes: ee05f456772d ("NFSv4: Fix races between open and delegreturn") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/delegation.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index c17ff82..1865322 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -255,13 +255,18 @@ void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) { + const struct cred *cred; int res = 0; - if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) - res = nfs4_proc_delegreturn(inode, - delegation->cred, + if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { + spin_lock(&delegation->lock); + cred = get_cred(delegation->cred); + spin_unlock(&delegation->lock); + res = nfs4_proc_delegreturn(inode, cred, &delegation->stateid, issync); + put_cred(cred); + } return res; } -- 2.7.4