FKIE_CVE-2026-31482

Vulnerability from fkie_nvd - Published: 2026-04-22 14:16 - Updated: 2026-04-23 16:17
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: s390/entry: Scrub r12 register on kernel entry Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"), all entry handlers loaded r12 with the current task pointer (lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That commit removed TIF_ISOLATE_BP, dropping both the branch prediction macros and the r12 load, but did not add r12 to the register clearing sequence. Add the missing xgr %r12,%r12 to make the register scrub consistent across all entry points.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0738d395aab8fae3b5a3ad3fc640630c91693c27
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7f4e3233faa8470dd0627bc49b2809f2bfebd909
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/95c899cd791803a5bf7b73e5994fbbe1cc1a9c36
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/99a8b420f3f0e162eb9c9c9253929d4d23f9bd30
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a58d298a83a3a9b7ca99ded9d60a1e77231159ef
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/entry: Scrub r12 register on kernel entry\n\nBefore commit f33f2d4c7c80 (\"s390/bp: remove TIF_ISOLATE_BP\"),\nall entry handlers loaded r12 with the current task pointer\n(lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That\ncommit removed TIF_ISOLATE_BP, dropping both the branch prediction\nmacros and the r12 load, but did not add r12 to the register clearing\nsequence.\n\nAdd the missing xgr %r12,%r12 to make the register scrub consistent\nacross all entry points."
    }
  ],
  "id": "CVE-2026-31482",
  "lastModified": "2026-04-23T16:17:41.280",
  "metrics": {},
  "published": "2026-04-22T14:16:45.457",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0738d395aab8fae3b5a3ad3fc640630c91693c27"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7f4e3233faa8470dd0627bc49b2809f2bfebd909"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/95c899cd791803a5bf7b73e5994fbbe1cc1a9c36"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/99a8b420f3f0e162eb9c9c9253929d4d23f9bd30"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a58d298a83a3a9b7ca99ded9d60a1e77231159ef"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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