s390/zcrypt: Improve CCA CPRB length and overflow checks

{
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  "url": "https://osv.dev/vulnerability/CVE-2026-80546",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "s390/zcrypt: Improve CCA CPRB length and overflow checks",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Improve CCA CPRB length and overflow checks The xcrb_msg_to_type6cprb_msgx() function lacks proper input validation, creating security vulnerabilities: 1. Integer overflow after CEIL4 alignment: Signed int variables could overflow during 4-byte boundary alignment, causing undersized buffer allocations or incorrect bounds checking. 2. Missing minimum size validation: The CPRBX structure is copied from userspace without verifying sufficient buffer length. Undersized buffers cause uninitialized memory access when reading structure fields like cprbx.cprb_len and cprbx.domain. 3. Arithmetic overflow in sum calculations: Adding control block and data block sizes could overflow, bypassing size checks and enabling buffer overflows. Fix by using size_t for length calculations, adding U32_MAX boundary checks after alignment, validating minimum control block size before copying from userspace, and detecting sum calculation overflows.",
    "evidence": "osv:CVE-2026-80546",
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          "value": "Kernel",
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      "aliases": [
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      "modified": "2026-10-28T02:30:27.058276748Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/35ac6754ba6da45fd193f5ce3f665f7490b830d5",
        "https://git.kernel.org/stable/c/50fe5133dcb46449daf2435fa705264364411129",
        "https://git.kernel.org/stable/c/584400144020f40365de3972c4763da520e7280e",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80546.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80546",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
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    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 493593,
  "published_at": "2026-08-26T14:37:17.55+00:00"
}