{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-46922", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-25T13:45:52.719Z", "datePublished": "2024-02-27T09:36:27.145Z", "dateUpdated": "2026-08-05T08:45:06.331Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:45:06.331Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKEYS: trusted: Fix TPM reservation for seal/unseal\n\nThe original patch 8c657a0590de (\"KEYS: trusted: Reserve TPM for seal\nand unseal operations\") was correct on the mailing list:\n\nhttps://lore.kernel.org/linux-integrity/20210128235621.127925-4-jarkko@kernel.org/\n\nBut somehow got rebased so that the tpm_try_get_ops() in\ntpm2_seal_trusted() got lost. This causes an imbalanced put of the\nTPM ops and causes oopses on TIS based hardware.\n\nThis fix puts back the lost tpm_try_get_ops()" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached via the local add_key/keyctl syscall path (trusted_instantiate → trusted_tpm_seal → tpm2_seal_trusted), not via network packets or physical device I/O.\nAC:L - An attacker can reliably trigger the imbalanced tpm_put_ops by creating a TPM2 trusted key (e.g. keyctl add trusted ... \"new 32\"); no race or attacker-uncontrollable condition is required, and put runs even when the TPM command fails.\nPR:L - Creating a trusted key requires only an unprivileged local account with write access to a keyring the caller possesses (documented as keyctl add trusted ... @u); there is no capability check in the trusted-key instantiate path.\nUI:N - The attacker invokes add_key/keyctl directly; no separate victim action is required.\nS:U - Impact is confined to the host kernel privilege domain (lock/refcount corruption and potential tpm_chip UAF); it does not cross a VM, IOMMU, or other security authority boundary.\nC:H - tpm_put_ops without a matching tpm_try_get_ops drops a real device reference via put_device and can free the still-referenced tpm_chip, yielding a heap use-after-free that can be leveraged for arbitrary memory disclosure.\nI:H - The same premature free of tpm_chip (which contains ops function pointers), plus unlocking an unheld tpm_mutex and up_read of ops_sem, enables heap reuse and control-flow hijacking primitives under UAF guidance.\nA:H - The fix commit documents kernel oopses on TIS hardware from the imbalanced put, and the resulting UAF/lock corruption can crash or destabilize the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/keys/trusted-keys/trusted_tpm2.c" ], "versions": [ { "version": "67118bb78d72aab5b831f054a74ae856339a1974", "lessThan": "bf84ef2dd2ccdcd8f2658476d34b51455f970ce4", "status": "affected", "versionType": "git" }, { "version": "498b8fc1cdc13b57b02dd28544b18323900fae10", "lessThan": "39c8d760d44cb3fa0d67e8cd505df81cf4d80999", "status": "affected", "versionType": "git" }, { "version": "8c657a0590de585b1115847c17b34a58025f2f4b", "lessThan": "9d5171eab462a63e2fbebfccf6026e92be018f20", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/keys/trusted-keys/trusted_tpm2.c" ], "versions": [ { "version": "5.10.20", "lessThan": "5.10.33", "status": "affected", "versionType": "semver" }, { "version": "5.11.3", "lessThan": "5.11.17", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.20", "versionEndExcluding": "5.10.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11.3", "versionEndExcluding": "5.11.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bf84ef2dd2ccdcd8f2658476d34b51455f970ce4" }, { "url": "https://git.kernel.org/stable/c/39c8d760d44cb3fa0d67e8cd505df81cf4d80999" }, { "url": "https://git.kernel.org/stable/c/9d5171eab462a63e2fbebfccf6026e92be018f20" } ], "title": "KEYS: trusted: Fix TPM reservation for seal/unseal", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-07-25T16:00:18.491671Z", "id": "CVE-2021-46922", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-07-25T16:00:29.336Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.976Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/bf84ef2dd2ccdcd8f2658476d34b51455f970ce4", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/39c8d760d44cb3fa0d67e8cd505df81cf4d80999", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/9d5171eab462a63e2fbebfccf6026e92be018f20", "tags": [ "x_transferred" ] } ] } ] } }