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().

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf
https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f
https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8
https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e
https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b
https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc
https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-27 08:16

Updated : 2026-08-05 08:16

NVD link : CVE-2026-64534

Mitre link : CVE-2026-64534

CVE.ORG link : CVE-2026-64534

JSON object : View

Products Affected

No product.

CWE

No CWE.

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However, if the command\narrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()\nhad returned false and percpu_ref_tryget_live() was never executed. The\nunconditional percpu_ref_put() inside nvmet_req_uninit() then causes a\nrefcount underflow, leading to a WARNING in\npercpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and\neventually a permanent workqueue deadlock.\n\nCheck cmd->flags & NVMET_TCP_F_INIT_FAILED before calling\nnvmet_req_uninit(), matching the existing pattern in\nnvmet_tcp_execute_request()."}], "lastModified": "2026-08-05T08:16:35.860", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}