CVE-2025-37871

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

nfsd: decrease sc_count directly if fail to queue dl_recall

A deadlock warning occurred when invoking nfs4_put_stid following a failed

dl_recall queue operation:

T1 T2

nfs4_laundromat

nfs4_get_client_reaplist

nfs4_anylock_blockers

__break_lease

spin_lock // ctx->flc_lock

spin_lock // clp->cl_lock

nfs4_lockowner_has_blockers

locks_owner_has_blockers

spin_lock // flctx->flc_lock

nfsd_break_deleg_cb

nfsd_break_one_deleg

nfs4_put_stid

refcount_dec_and_lock

spin_lock // clp->cl_lock

When a file is opened, an nfs4_delegation is allocated with sc_count

initialized to 1, and the file_lease holds a reference to the delegation.

The fi

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References