{"id":"CVE-2026-64534","state":"PUBLISHED","title":"nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path","description":"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 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().","publishedAt":"2026-07-27T06:32:34.301Z","updatedAt":"2026-10-19T20:48:38.863Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"91edfca6f8b364d60cde3ddefaf7d03ddf35774b","status":"affected","lessThan":"22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"c7874dad84b20433c0fe3919f291a762d40de08b","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"d306da8833e75f669d93424fd84940236f3850bc","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"2ed3c9d955e8cd6361f130623baa664a75fb345f","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"4606467a75cfc16721937272ed29462a750b60c8","versionType":"git"},{"version":"4b17476d809273617d3317fa0d4ae78aa488d760","status":"affected","versionType":"git"},{"version":"5.10.20","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.11.3","status":"affected","lessThan":"5.12","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/tcp.c"]}],"references":["https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf","https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e","https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b","https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1","https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc","https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f","https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8"],"weaknesses":["CWE-667"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64534.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64534","state":"PUBLISHED","datePublished":"2026-07-27T06:32:34.301Z","dateUpdated":"2026-10-19T20:48:38.863Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.795Z"},"containers":{"cna":{"title":"nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path","descriptions":[{"lang":"en","value":"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 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()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"91edfca6f8b364d60cde3ddefaf7d03ddf35774b","status":"affected","lessThan":"22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"c7874dad84b20433c0fe3919f291a762d40de08b","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"d306da8833e75f669d93424fd84940236f3850bc","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"2ed3c9d955e8cd6361f130623baa664a75fb345f","versionType":"git"},{"version":"fda871c0ba5d2eed2cd1c881573168129da70058","status":"affected","lessThan":"4606467a75cfc16721937272ed29462a750b60c8","versionType":"git"},{"version":"4b17476d809273617d3317fa0d4ae78aa488d760","status":"affected","versionType":"git"},{"version":"5.10.20","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.11.3","status":"affected","lessThan":"5.12","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/tcp.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable NVMe/TCP target receive path processes attacker-supplied ICReq, CapsuleCmd, inline payload, and digest data over an Internet-routable TCP connection.\nAC:L - The attacker can negotiate data digests and reliably send a rejected write command with inline data followed by an incorrect digest; no race or condition outside the attacker's control is required.\nPR:N - A malformed CapsuleCmd can trigger this path before CONNECT, host-NQN ACL evaluation, or DH-HMAC-CHAP authentication, so the remote attacker needs no credentials or privileges.\nUI:N - The target processes the malicious protocol sequence automatically without any victim action.\nS:U - The vulnerable transport and the affected kernel memory, execution, and storage resources belong to the same target-host security authority.\nC:H - The unmatched reference decrement can offset a legitimate in-flight request reference, allowing command structures and SGL pages to be freed while backend I/O still uses them; this UAF can expose arbitrary reused kernel memory.\nI:H - The premature freeing of request structures and I/O pages can let backend operations write through reallocated memory or corrupt completion control state, making arbitrary kernel writes and control-flow hijacking defensible.\nA:H - The basic trigger causes a submission-queue refcount underflow and permanent workqueue deadlock, while UAF variants can crash the kernel; unauthenticated attackers can repeat the trigger across connections."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:42:44.214Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.20","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64534","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:41:53.789221Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-667","lang":"en","type":"CWE","description":"CWE-667 Improper Locking"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:48:38.863Z"}}]}}}