From: Trond Myklebust Date: Mon, 3 Mar 2014 03:03:12 +0000 (-0500) Subject: NFS: Fix a delegation callback race X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=40cb674a5a0cff49a46af150fb862229e545e908;p=linux-edison.git NFS: Fix a delegation callback race commit 755a48a7a4eb05b9c8424e3017d947b2961a60e0 upstream. The clean-up in commit 36281caa839f ended up removing a NULL pointer check that is needed in order to prevent an Oops in nfs_async_inode_return_delegation(). Reported-by: "Yan, Zheng" Link: http://lkml.kernel.org/r/5313E9F6.2020405@intel.com Fixes: 36281caa839f (NFSv4: Further clean-ups of delegation stateid validation) Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 57db3244f4d..4b49a8c6cca 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -656,16 +656,19 @@ int nfs_async_inode_return_delegation(struct inode *inode, rcu_read_lock(); delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation == NULL) + goto out_enoent; - if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) { - rcu_read_unlock(); - return -ENOENT; - } + if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) + goto out_enoent; nfs_mark_return_delegation(server, delegation); rcu_read_unlock(); nfs_delegation_run_state_manager(clp); return 0; +out_enoent: + rcu_read_unlock(); + return -ENOENT; } static struct inode *