In the Linux kernel, the following vulnerability has been resolved: 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.
https://git.kernel.org/stable/c/d662f7fc04fde305a27f304b3cd19b614d366839
https://git.kernel.org/stable/c/51af080ca4e553256c59a75a877b9b4fff828311
https://git.kernel.org/stable/c/4c7fc129db061c7daab841c4f3c342d894832362
https://git.kernel.org/stable/c/07adfbb3de7529f58ca708a97ead7fa4fdb71056