CVE-2026-64534

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path

CRITICAL
9.8
CVSS Score
Published: July 27, 2026 at 06:32 AM UTC
Updated: October 19, 2026 at 09:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
CRITICAL9.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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().

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4b17476d809273617d3317fa0d4ae78aa488d7605.10.205.11.35.1291edfca6f8b364d60cde3ddefaf7d03ddf35774bfda871c0ba5d2eed2cd1c881573168129da70058
Vendor states this is fixed in 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf (fixed)
Vendor states this is fixed in 2ed3c9d955e8cd6361f130623baa664a75fb345f (fixed)
Vendor states this is fixed in 4606467a75cfc16721937272ed29462a750b60c8 (fixed)
Vendor states this is fixed in ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e (fixed)
Vendor states this is fixed in c7874dad84b20433c0fe3919f291a762d40de08b (fixed)
Vendor states this is fixed in d306da8833e75f669d93424fd84940236f3850bc (fixed)
Vendor states this is fixed in e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1 (fixed)
Vendor states this is fixed in 5.10.261 (unaffected)
Vendor states this is fixed in 5.12 (unaffected)
Vendor states this is fixed in 5.15.212 (unaffected)
Vendor states this is fixed in 6.1.178 (unaffected)
Vendor states this is fixed in 6.12.97 (unaffected)
Vendor states this is fixed in 6.18.40 (unaffected)
Vendor states this is fixed in 6.6.145 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

9.8CRITICALLinux
Vector?

Quick Info

StatusRECEIVED
CWE
CWE-667

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