{"id":"CVE-2026-64534","title":"nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path\n\nIn nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,\nnvmet_req_uninit() is…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 91edfca6f8b364d60cde3ddefaf7d03ddf35774b < 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < c7874dad84b20433c0fe3919f291a762d40de08b","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < d306da8833e75f669d93424fd84940236f3850bc","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < 2ed3c9d955e8cd6361f130623baa664a75fb345f","Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < 4606467a75cfc16721937272ed29462a750b60c8","Linux 4b17476d809273617d3317fa0d4ae78aa488d760","Linux >= 5.10.20 < 5.10.261","Linux >= 5.11.3 < 5.12","Linux 5.12"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:41:53.789221Z"},"published":"2026-07-27","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:40.408Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64534","references":[{"url":"https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf"},{"url":"https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e"},{"url":"https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b"},{"url":"https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1"},{"url":"https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc"},{"url":"https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f"},{"url":"https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8"}],"tags":["cve.org"],"epss":0.00419,"epssPercentile":0.34684,"ingestedAt":"2026-10-16T17:24:46.827Z","slug":"CVE-2026-64534","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path\n\nIn nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,\nnvmet_req_uninit() is called unconditionally. 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().\n\n## Affected\n\n- `Linux >= 91edfca6f8b364d60cde3ddefaf7d03ddf35774b < 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < c7874dad84b20433c0fe3919f291a762d40de08b`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < d306da8833e75f669d93424fd84940236f3850bc`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < 2ed3c9d955e8cd6361f130623baa664a75fb345f`\n- `Linux >= fda871c0ba5d2eed2cd1c881573168129da70058 < 4606467a75cfc16721937272ed29462a750b60c8`\n- `Linux 4b17476d809273617d3317fa0d4ae78aa488d760`\n- `Linux >= 5.10.20 < 5.10.261`\n- `Linux >= 5.11.3 < 5.12`\n- `Linux 5.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}