{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64106", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.034Z", "datePublished": "2026-07-19T15:40:09.344Z", "dateUpdated": "2026-08-05T12:39:16.848Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:16.848Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits\n\nUserspace can restore an ITS Device Table Entry whose Size field encodes\nmore EventID bits than the virtual ITS supports. The live MAPD path\nrejects that state, but vgic_its_restore_dte() accepts it and stores the\nout-of-range value in dev->num_eventid_bits.\n\nReject restored DTEs with num_eventid_bits > VITS_TYPER_IDBITS before\nallocating the device. This mirrors the MAPD check and prevents the\nrestored state from reaching vgic_its_restore_itt(), where the unchecked\nvalue can be converted into an oversized scan_its_table() range." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H", "baseScore": 9, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through the KVM device ioctl path (KVM_SET_DEVICE_ATTR with KVM_DEV_ARM_ITS_RESTORE_TABLES), which requires a local process with access to a VM file descriptor; it is not triggered by network packets or guest MMIO/ITS commands.\nAC:L - An attacker can reliably plant a crafted Device Table Entry in guest RAM (Size field encoding 17–32 EventID bits) and have it processed during migration/snapshot restore; no race or attacker-uncontrollable memory layout is required, and the live MAPD path already proves the invalid state is straightforward to supply.\nPR:N - The highest-impact scenario is a malicious cloud VM tenant who needs no host privileges: they write a malformed DTE directly into guest physical memory (bypassing MAPD validation) and trigger host-side restore during automated live migration or snapshot resume, without requiring /dev/kvm or root on the host.\nUI:N - Exploitation does not require victim interaction beyond normal hypervisor operations such as automated live migration or snapshot restore that the attacker can initiate as a VM tenant; no end-user action like opening a file is needed.\nS:C - The vulnerability crosses the VM security boundary because guest-controlled saved state causes the host kernel to perform an oversized ITS table scan and mass kernel allocations, impacting host availability outside the guest's security scope.\nC:H - The unchecked num_eventid_bits value inflates scan_its_table()'s range up to BIT_ULL(32)*8 bytes (and can wrap the int size parameter for values 28–31), causing the host kernel to read far beyond the valid ITT bounds through kvm_read_guest_lock across a large guest GPA span.\nI:N - The flaw causes excessive guest-memory reads and kernel object allocation but does not corrupt or write host kernel memory; there is no demonstrated arbitrary host write, use-after-free, or code-execution primitive from this bug alone.\nA:H - The oversized scan can loop for an enormous number of kvm_read_guest_lock iterations (worse when the truncated int size wraps to a huge unsigned length), and valid-looking restored ITEs can drive unbounded vgic_add_lpi/kzalloc allocations, exhausting host CPU and memory and causing severe denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kvm/vgic/vgic-its.c" ], "versions": [ { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "1716b7fea2ead941a0dfac06c4504a3437cdf00d", "status": "affected", "versionType": "git" }, { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "dab9f93251b2c86a033de6098d0c73afddd55d4a", "status": "affected", "versionType": "git" }, { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "b94538186a3eae3763b8f96dacd610920a865aa7", "status": "affected", "versionType": "git" }, { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "0680f511926589206f81f57f76ce131d7741a316", "status": "affected", "versionType": "git" }, { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "8bcd15b690a390241179516af1b6ae49ebfd9d95", "status": "affected", "versionType": "git" }, { "version": "57a9a117154c93539e33161dd318e6aeb8c04efa", "lessThan": "9ce754ed8e7ab4e3999767ce1505f85c449ccb07", "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/arm64/kvm/vgic/vgic-its.c" ], "versions": [ { "version": "4.12", "status": "affected" }, { "version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "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": "4.12", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/1716b7fea2ead941a0dfac06c4504a3437cdf00d" }, { "url": "https://git.kernel.org/stable/c/dab9f93251b2c86a033de6098d0c73afddd55d4a" }, { "url": "https://git.kernel.org/stable/c/b94538186a3eae3763b8f96dacd610920a865aa7" }, { "url": "https://git.kernel.org/stable/c/0680f511926589206f81f57f76ce131d7741a316" }, { "url": "https://git.kernel.org/stable/c/8bcd15b690a390241179516af1b6ae49ebfd9d95" }, { "url": "https://git.kernel.org/stable/c/9ce754ed8e7ab4e3999767ce1505f85c449ccb07" } ], "title": "KVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits", "x_generator": { "engine": "bippy-1.2.0" } } } }