{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49886", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-05-01T14:05:17.241Z", "datePublished": "2025-05-01T14:10:31.933Z", "dateUpdated": "2026-08-05T08:56:34.143Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:56:34.143Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/tdx: Panic on bad configs that #VE on \"private\" memory access\n\nAll normal kernel memory is \"TDX private memory\". This includes\neverything from kernel stacks to kernel text. Handling\nexceptions on arbitrary accesses to kernel memory is essentially\nimpossible because they can happen in horribly nasty places like\nkernel entry/exit. But, TDX hardware can theoretically _deliver_\na virtualization exception (#VE) on any access to private memory.\n\nBut, it's not as bad as it sounds. TDX can be configured to never\ndeliver these exceptions on private memory with a \"TD attribute\"\ncalled ATTR_SEPT_VE_DISABLE. The guest has no way to *set* this\nattribute, but it can check it.\n\nEnsure ATTR_SEPT_VE_DISABLE is set in early boot. panic() if it\nis unset. There is no sane way for Linux to run with this\nattribute clear so a panic() is appropriate.\n\nThere's small window during boot before the check where kernel\nhas an early #VE handler. But the handler is only for port I/O\nand will also panic() as soon as it sees any other #VE, such as\na one generated by a private memory access.\n\n[ dhansen: Rewrite changelog and rebase on new tdx_parse_tdinfo().\n\t Add Kirill's tested-by because I made changes since\n\t he wrote this. ]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The attacker is the untrusted TDX VMM/hypervisor on the same host, inducing private-memory #VEs by leaving ATTR_SEPT_VE_DISABLE unset and placing Secure-EPT entries in PENDING; this is a platform-local SEPT/TD-config surface, not a network path.\nAC:L - The VMM fully controls TD attributes and SEPT state (REMOVE/AUG to PENDING) and can trigger #VEs on kernel private pages during the SYSCALL/SYSRET gap at will, with no race or layout dependency outside its control.\nPR:N - Under the TDX threat model the VMM has no authorized privileges inside the Trust Domain; no guest account, capability, or authentication is required to withhold SEPT_VE_DISABLE or manipulate SEPT entries.\nUI:N - No victim user action is required; ordinary guest syscalls and kernel memory accesses hit the vulnerable entry window while the VMM injects private-memory #VEs.\nS:U - Compromise stays within the guest kernel/userspace security authority (guest privilege escalation or crash); this is not a guest-to-host escape or direct host R/W of guest-private pages across the CoCo boundary.\nC:H - Intel documents that a #VE in the SYSCALL gap (kernel running on the user stack) lets malicious guest userspace take over the guest kernel, yielding arbitrary disclosure of TD memory and secrets.\nI:H - The same entry-gap #VE enables full guest-kernel control-flow hijack and privilege escalation, so integrity impact is complete arbitrary modification within the TD.\nA:H - #VE on private memory in entry/NMI paths also produces oops, #DF, or panic, and successful kernel takeover implies full guest availability loss, all triggerable repeatedly by the VMM." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/coco/tdx/tdx.c" ], "versions": [ { "version": "9a22bf6debbf5169f750af53c7f86eb4e3cd6712", "lessThan": "895c168c8f78079f21ad50fead7593ffa352f795", "status": "affected", "versionType": "git" }, { "version": "9a22bf6debbf5169f750af53c7f86eb4e3cd6712", "lessThan": "373e715e31bf4e0f129befe87613a278fac228d3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/coco/tdx/tdx.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.8", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1", "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": "5.19", "versionEndExcluding": "6.0.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/895c168c8f78079f21ad50fead7593ffa352f795" }, { "url": "https://git.kernel.org/stable/c/373e715e31bf4e0f129befe87613a278fac228d3" } ], "title": "x86/tdx: Panic on bad configs that #VE on \"private\" memory access", "x_generator": { "engine": "bippy-1.2.0" } } } }