CVE-2026-64534

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected, nvmet_req_uninit() is called unconditionally. However, if the command arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init() had returned false and percpu_ref_tryget_live() was never executed. The unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a refcount underflow, leading to a WARNING in percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and eventually a permanent workqueue deadlock. Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling nvmet_req_uninit(), matching the existing pattern in nvmet_tcp_execute_request().

Package Linux Kernel
Published 2026-07-27
Last modified 2026-07-27
Patch available
Yes

Affected versions

Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1 and their respective stable series.

Fixed in
✓ 5.10.261 5.10.x ✓ 5.15.212 5.15.x ✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.97 6.12.x ✓ 6.18.40 6.18.x ✓ 7.1

Frequently asked questions

  • What is CVE-2026-64534?

    CVE-2026-64534 is a unscored severity Linux kernel vulnerability . CVE-2026-64534 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-64534?

    Yes. CVE-2026-64534 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others.

  • Is CVE-2026-64534 actively exploited?

    No. CVE-2026-64534 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.