In the Linux kernel, the following vulnerability has been resolved:NFSD: fix hang in nfsd4_shutdown_callbackIf nfs4_client is in courtesy state then there is no point to sendthe callback. This causes nfsd4_shutdown_callback to hang sincecl_cb_inflight is not 0. This hang lasts about 15 minutes until TCPnotifies NFSD that the connection was dropped.This patch modifies nfsd4_run_cb_work to skip the RPC call ifnfs4_client is in courtesy state.
No PoCs from references.
- https://github.com/w4zu/Debian_security