lockd: fix NULL dereference on lockowner allocation failure

nlmclnt_locks_init_private() installs NLM file lock operations even when
nlmclnt_find_lockowner() fails to allocate a lockowner. nlmclnt_proc()
then returns -ENOMEM, but the VFS still tears down the partially
initialized file_lock and calls locks_release_private().

That invokes nlmclnt_locks_release_private(), which dereferences
fl->fl_u.nfs_fl.owner and crashes because the owner was never installed.

Clear fl_ops before attempting to initialize the NLM private state, and
install the NLM lock operations only after a lockowner has been allocated
successfully.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

0 files changed, 0 insertions, 0 deletions