alpha: fix user-space corruption during memory compaction
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.
CVE-2026-43258
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-43258
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "a48d07afdf18212de22b959715b16793c5a6e57a",
"lessThan": "5593c9b255ae73f57a8b5e696a660032acbd67da",
"versionType": "git"
},
{
"status": "affected",
"version": "a48d07afdf18212de22b959715b16793c5a6e57a",
"lessThan": "d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6",
"versionType": "git"
},
{
"status": "affected",
"version": "a48d07afdf18212de22b959715b16793c5a6e57a",
"lessThan": "03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f",
"versionType": "git"
},
{
"status": "affected",
"version": "a48d07afdf18212de22b959715b16793c5a6e57a",
"lessThan": "bab8d762a8dbb816b10011e13b87d1bca91e5f77",
"versionType": "git"
},
{
"status": "affected",
"version": "a48d07afdf18212de22b959715b16793c5a6e57a",
"lessThan": "dd5712f3379cfe760267cdd28ff957d9ab4e51c7",
"versionType": "git"
}
],
"programFiles": [
"arch/alpha/include/asm/pgtable.h",
"arch/alpha/include/asm/tlbflush.h",
"arch/alpha/mm/Makefile",
"arch/alpha/mm/tlbflush.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.75",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.16",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.6",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/alpha/include/asm/pgtable.h",
"arch/alpha/include/asm/tlbflush.h",
"arch/alpha/mm/Makefile",
"arch/alpha/mm/tlbflush.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-43258
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46279 · Revision 1
- Added to Heist Feed
- Publisher date