CVE-2025-39688 Information

Description

In the Linux kernel the following vulnerability has been resolved:

nfsd: allow SC_STATUS_FREEABLE when searching via nfs4_lookup_stateid()

The pynfs DELEG8 test fails when run against nfsd. It acquires a delegation and then lets the lease time out. It then tries to use the deleg stateid and expects to see NFS4ERR_DELEG_REVOKED but it gets bad NFS4ERR_BAD_STATEID instead.

When a delegation is revoked it’s initially marked with SC_STATUS_REVOKED or SC_STATUS_ADMIN_REVOKED and later it’s marked with the SC_STATUS_FREEABLE flag which denotes that it is waiting for s FREE_STATEID call.

nfs4_lookup_stateid() accepts a statusmask that includes the status flags that a found stateid is allowed to have. Currently that mask never includes SC_STATUS_FREEABLE which means that revoked delegations are (almost) never found.

Add SC_STATUS_FREEABLE to the always-allowed status flags and remove it from nfsd4_delegreturn() since it’s now always implied.

Reference

https://git.kernel.org/stable/c/52e209203c35a4fbff8af23cd3613efe5df40102 https://git.kernel.org/stable/c/5bcb44e650bc4ec7eac23df90c5e011a77fa2beb https://git.kernel.org/stable/c/d1bc15b147d35b4cb7ca99a9a7d79d41ca342c13 https://git.kernel.org/stable/c/dc6f3295905d7185e71091870119a8c11c3808cc