Answer in brief
CVE-2026-93066 records a Unknown severity vulnerability in x86/mm/pat: Take cpa_lock around large-page collapse. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=41d88484c71cd4f659348da41b7b5b3dbd3be1f6 <591b6fac9df3f43522e8ff6eed8662f8b6f1a124 || >=41d88484c71cd4f659348da41b7b5b3dbd3be1f6 <fb97d1d6c20692e15247fa5c8b894b2325e38aee || >=41d88484c71cd4f659348da41b7b5b3dbd3be1f6 <1aac65f3e651334259ecb2a5f5ddb81c01f02599 | 591b6fac9df3f43522e8ff6eed8662f8b6f1a124, fb97d1d6c20692e15247fa5c8b894b2325e38aee, 1aac65f3e651334259ecb2a5f5ddb81c01f02599 |
| Linux/Linuxgeneric | 6.15 | Not reported |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: x86/mm/pat: Take cpa_lock around large-page collapse Loading and unloading modules concurrently on several CPUs on a KASAN build, with a short delay injected at the CPA page-table lookup to widen the window, faults within minutes: BUG: KASAN: use-after-free in __change_page_attr+0x7cc/0x7e0 Write of size 8 at addr ffff888181139718 by task modprobe ... The buggy address belongs to the physical page: pfn:0x181139 ... page_type: f2(table) cpa_collapse_large_pages() rebuilds a leaf PMD from its 4K PTEs and frees the old PTE-table pages, while __change_page_attr() fetches a PTE pointer from a lockless lookup_address_in_pgd_attr() and writes it with set_pte_atomic() only later. When module text is served from a shared large ROX mapping the two run on the same PMD: CPU A (module load) CPU B (module finalize) ------------------- ----------------------- execmem_make_temp_rw set_memory_nx __change_page_attr split 2M -> 4K table P kpte = &P[i] (lockless) execmem_restore_rox set_memory_rox (CPA_COLLAPSE) cpa_collapse_large_pages rebuild leaf PMD flush_tlb_all pagetable_free(P) set_pte_atomic(kpte, ...) -> writes into freed P P is a page-table page (page_type: table), reused at once, so the write corrupts whatever got the page next: a bad-pte or bad-page splat, or a fatal fault once P has been turned into read-only text. The flush_tlb_all() before the free does not close this: its IPI only serializes against page-table walkers that run with interrupts off (e.g. GUP-fast); the walk in __change_page_attr() runs with interrupts on, so nothing stops it from holding a stale pointer into P. Serialize the collapse - the PMD rebuild, TLB flush and PTE-table free - under cpa_lock, the same lock __change_page_attr() now takes unconditionally since commit ("x86/mm/pat: stop gating cpa_lock on debug_pagealloc_enabled()"), so a concurrent walker can no longer hold a pointer into a table the collapse is about to free.
Quoted source text, attributed separately from HOL analysis.