CVE-2026-90038

Summary

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

NFSD: Prevent client use-after-free during export state revocation

nfsd4_revoke_export_states() has the same use-after-free as nfsd4_revoke_states(): it drops nn->client_lock across revoke_one_stid() and the following read of clp->cl_minorversion, but the stateid reference it holds does not pin the client. A teardown racing the dropped lock can free the client while revoke_one_stid() still dereferences it.

exportfs -u drives this path through NFSD_CMD_UNLOCK_EXPORT, so an administrator removing an export can race a client expiry.

Skip a client that is already expiring and otherwise pin it with cl_rpc_users under client_lock before dropping the lock, matching nfsd4_revoke_states().

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2eac189bb059d31a29937b29ee0f477394198610 < c05ae58fe06ce2ac34312f649e71c3596bdde358affected
LinuxLinux2eac189bb059d31a29937b29ee0f477394198610 < 2108de53568a64936a0da3e04d85c35df98d3fb6affected
LinuxLinux7.2affected
LinuxLinux0 < 7.2unaffected
LinuxLinux7.2.5 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References