{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64534", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.795Z", "datePublished": "2026-07-27T06:32:34.301Z", "dateUpdated": "2026-08-05T12:42:44.214Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:42:44.214Z" }, "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()." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "91edfca6f8b364d60cde3ddefaf7d03ddf35774b", "lessThan": "22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "c7874dad84b20433c0fe3919f291a762d40de08b", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "d306da8833e75f669d93424fd84940236f3850bc", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "2ed3c9d955e8cd6361f130623baa664a75fb345f", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "4606467a75cfc16721937272ed29462a750b60c8", "status": "affected", "versionType": "git" }, { "version": "4b17476d809273617d3317fa0d4ae78aa488d760", "status": "affected", "versionType": "git" }, { "version": "5.10.20", "lessThan": "5.10.261", "status": "affected", "versionType": "semver" }, { "version": "5.11.3", "lessThan": "5.12", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "5.12", "status": "affected" }, { "version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "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" } ] } ] } ], "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" } ], "title": "nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path", "x_generator": { "engine": "bippy-1.2.0" } } } }