CVE-2026-74403 (GCVE-0-2026-74403)
Vulnerability from cvelistv5
Published
2026-08-15 05:59
Modified
2026-08-17 05:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Check for page allocation failure correctly in TIO
Sashiko notes:
> if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it
> safe to pass it directly to page_address()?
>
> On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might
> compute a deterministic but invalid, non-zero virtual address. The
> subsequent if (tio_status) check would then evaluate to true, and
> sev_tsm_init_locked() would dereference the invalid pointer.
Indeed, page_address(NULL) will return non-NULL garbage here. Fix this by
checking the page allocation itself for NULL, not the resulting virtual
address.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/crypto/ccp/sev-dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69",
"status": "affected",
"version": "4be423572da1f4c11f45168e3fafda870ddac9f8",
"versionType": "git"
},
{
"lessThan": "a8d5370eef00eca132a292b1901c9914c817e385",
"status": "affected",
"version": "4be423572da1f4c11f45168e3fafda870ddac9f8",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/crypto/ccp/sev-dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.19"
},
{
"lessThan": "6.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Check for page allocation failure correctly in TIO\n\nSashiko notes:\n\n\u003e if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it\n\u003e safe to pass it directly to page_address()?\n\u003e\n\u003e On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might\n\u003e compute a deterministic but invalid, non-zero virtual address. The\n\u003e subsequent if (tio_status) check would then evaluate to true, and\n\u003e sev_tsm_init_locked() would dereference the invalid pointer.\n\nIndeed, page_address(NULL) will return non-NULL garbage here. Fix this by\nchecking the page allocation itself for NULL, not the resulting virtual\naddress."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The flaw is in __sev_snp_init_locked() reached only through sev_platform_init() via KVM_SEV_INIT/KVM_SEV_INIT2 ioctls on /dev/kvm or kernel boot init; SEV-TIO platform setup has no network-facing entry point.\nAC:L - An attacker who can trigger first-time SNP init (e.g. psp_init_on_probe=0) can concurrently exhaust host memory to force __snp_alloc_firmware_pages() to return NULL and reliably reach the faulty page_address(NULL) path.\nPR:L - Reaching this code requires opening /dev/kvm and issuing KVM SNP initialization ioctls, which needs CAP_SYS_ADMIN obtainable by an unprivileged user inside a user namespace.\nUI:N - Exploitation needs only attacker-initiated KVM ioctls or boot-time SNP initialization; no action by another user or victim is required.\nS:U - Impact is confined to the host kernel during SNP-TIO initialization (oops, memory corruption); it does not cross a VM, container, or IOMMU security boundary.\nC:H - page_address(NULL) yields a non-NULL direct-map pointer, so sev_tio_init_locked() dereferences invalid memory and passes a bogus physical address to PSP firmware via SEV_CMD_TIO_STATUS, enabling kernel memory disclosure.\nI:H - The invalid pointer causes unchecked reads/writes in sev_tio_init_locked() and may direct PSP firmware to write TIO status data to an unintended physical page, enabling exploitable memory corruption.\nA:H - Dereferencing the bogus page_address(NULL) result in sev_tsm_init_locked()/sev_tio_init_locked() can trigger a kernel oops or panic, crashing the host during SNP-TIO initialization."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:46:45.328Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69"
},
{
"url": "https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385"
}
],
"title": "crypto: ccp - Check for page allocation failure correctly in TIO",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74403",
"datePublished": "2026-08-15T05:59:13.399Z",
"dateReserved": "2026-08-15T05:44:03.892Z",
"dateUpdated": "2026-08-17T05:46:45.328Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…