Critical severity · published Jul 27, 2026
CVE-2026-64534
nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path
9.8
CVSS
0.3%
EPSS
No
On KEV
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().
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
91edfca6f8b364d60cde3ddefaf7d03ddf35774b before 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf; fda871c0ba5d2eed2cd1c881573168129da70058 before ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e; fda871c0ba5d2eed2cd1c881573168129da70058 before c7874dad84b20433c0fe3919f291a762d40de08b; fda871c0ba5d2eed2cd1c881573168129da70058 before e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1; fda871c0ba5d2eed2cd1c881573168129da70058 before d306da8833e75f669d93424fd84940236f3850bc; fda871c0ba5d2eed2cd1c881573168129da70058 before 2ed3c9d955e8cd6361f130623baa664a75fb345f; +5 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64534
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64534
git.kernel.org
https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf
git.kernel.org
https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f
git.kernel.org
https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8
git.kernel.org
https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e
git.kernel.org
https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b
git.kernel.org
https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc
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