High 7.8Published May 6, 2026

CVE-2026-43258alpha: fix user-space corruption during memory compaction

Updated under an hour ago (Oct 26, 2026, 11:30 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: alpha: fix user-space corruption during memory compaction Alpha systems can suffer sporadic user-space crashes and heap corruption when memory compaction is enabled. Symptoms include SIGSEGV, glibc allocator failures (e.g. "unaligned tcache chunk"), and compiler internal errors. The failures disappear when compaction is disabled or when using global TLB invalidation. The root cause is insufficient TLB shootdown during page migration. Alpha relies on ASN-based MM context rollover for instruction cache coherency, but this alone is not sufficient to prevent stale data or instruction translations from surviving migration. Fix this by introducing a migration-specific helper that combines: - MM context invalidation (ASN rollover), - immediate per-CPU TLB invalidation (TBI), - synchronous cross-CPU shootdown when required. The helper is used only by migration/compaction paths to avoid changing global TLB semantics. Additionally, update flush_tlb_other(), pte_clear(), to use READ_ONCE()/WRITE_ONCE() for correct SMP memory ordering. This fixes observed crashes on both UP and SMP Alpha systems.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from a48d07afdf18212de22b959715b16793c5a6e57a before 5593c9b255ae73f57a8b5e696a660032acbd67da; from a48d07afdf18212de22b959715b16793c5a6e57a before d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6; from a48d07afdf18212de22b959715b16793c5a6e57a before 03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f; from a48d07afdf18212de22b959715b16793c5a6e57a before bab8d762a8dbb816b10011e13b87d1bca91e5f77; from a48d07afdf18212de22b959715b16793c5a6e57a before dd5712f3379cfe760267cdd28ff957d9ab4e51c7	CNA record
linux linux_kernel linux:linux_kernel	from 2.6.16.1 before 6.12.75; from 6.13 before 6.18.16; from 6.19 before 6.19.6; 2.6.16; 2.6.16; 2.6.16; 2.6.16; 2.6.16; and 2 more ranges	NVD

References

References

https://git.kernel.org/stable/c/5593c9b255ae73f57a8b5e696a660032acbd67da
https://git.kernel.org/stable/c/d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6	patch
https://git.kernel.org/stable/c/03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f	patch
https://git.kernel.org/stable/c/bab8d762a8dbb816b10011e13b87d1bca91e5f77	patch
https://git.kernel.org/stable/c/dd5712f3379cfe760267cdd28ff957d9ab4e51c7	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.