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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-03-02 22:03:12 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-23 21:37:06 -0700 |
| commit | e877d416818ff7439d01f88bf6d70131a27f730e (patch) | |
| tree | fccf0e75c2259f7581b0c0de91b072c99e2fbdea | |
| parent | 02a4ed4a5b0febad6f129e65ab9ae4794b51a61b (diff) | |
| download | lwn-e877d416818ff7439d01f88bf6d70131a27f730e.tar.gz lwn-e877d416818ff7439d01f88bf6d70131a27f730e.zip | |
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" <zheng.z.yan@intel.com>
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 <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nfs/delegation.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 89af1d269274..16d16e56cc39 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -540,16 +540,19 @@ 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 * |