CVE-2026-31482
s390/entry: Scrub r12 register on kernel entry
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ f33f2d4c7c80c641f6ca3dfe5e7dfe1f91543780; < a58d298a83a3a9b7ca99ded9d60a1e77231159ef (affected, git) ≥ f33f2d4c7c80c641f6ca3dfe5e7dfe1f91543780; < 95c899cd791803a5bf7b73e5994fbbe1cc1a9c36 (affected, git) ≥ f33f2d4c7c80c641f6ca3dfe5e7dfe1f91543780; < 7f4e3233faa8470dd0627bc49b2809f2bfebd909 (affected, git) ≥ f33f2d4c7c80c641f6ca3dfe5e7dfe1f91543780; < 99a8b420f3f0e162eb9c9c9253929d4d23f9bd30 (affected, git) ≥ f33f2d4c7c80c641f6ca3dfe5e7dfe1f91543780; < 0738d395aab8fae3b5a3ad3fc640630c91693c27 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
6.4 (affected) ≥ 0; < 6.4 (unaffected, semver) ≥ 6.6.131; ≤ 6.6.* (unaffected, semver) ≥ 6.12.80; ≤ 6.12.* (unaffected, semver) ≥ 6.18.21; ≤ 6.18.* (unaffected, semver) ≥ 6.19.11; ≤ 6.19.* (unaffected, semver) ≥ 7.0; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/a58d298a83a3a9b7ca99ded9d60a1e77231159efCNA: Linux
- https://git.kernel.org/stable/c/95c899cd791803a5bf7b73e5994fbbe1cc1a9c36CNA: Linux
- https://git.kernel.org/stable/c/7f4e3233faa8470dd0627bc49b2809f2bfebd909CNA: Linux
- https://git.kernel.org/stable/c/99a8b420f3f0e162eb9c9c9253929d4d23f9bd30CNA: Linux
- https://git.kernel.org/stable/c/0738d395aab8fae3b5a3ad3fc640630c91693c27CNA: Linux
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