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CVE-2026-45942: Linux, състезание за ресурс

7.8

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се локално, без особени условия, с обикновен потребителски вход и без действие от потребителя.

CVE радар: още уязвимости от този вид

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: ext4: fix e4b bitmap inconsistency reports A bitmap inconsistency issue was observed during stress tests under mixed huge-page workloads. Ext4 reported multiple e4b bitmap check failures like: ext4_mb_complex_scan_group:2508: group 350, 8179 free clusters as per group info. But got 8192 blocks Analysis and experimentation confirmed that the issue is caused by a race condition between page migration and bitmap modification. Although this timing window is extremely narrow, it is still hit in practice: folio_lock ext4_mb_load_buddy __migrate_folio check ref count folio_mc_copy __filemap_get_folio folio_try_get(folio) ...... mb_mark_used ext4_mb_unload_buddy __folio_migrate_mapping folio_ref_freeze folio_unlock The root cause of this issue is that the fast path of load_buddy only increments the folio's reference count, which is insufficient to prevent concurrent folio migration. We observed that the folio migration process acquires the folio lock. Therefore, we can determine whether to take the fast path in load_buddy by checking the lock status. If the folio is locked, we opt for the slow path (which acquires the lock) to close this concurrency window. Additionally, this change addresses the following issues: When the DOUBLE_CHECK macro is enabled to inspect bitmap-related issues, the following error may be triggered: corruption in group 324 at byte 784(6272): f in copy != ff on disk/prealloc Analysis reveals that this is a false positive. There is a specific race window where the bitmap and the group descriptor become momentarily inconsistent, leading to this error report: ext4_mb_load_buddy ext4_mb_load_buddy __filemap_get_folio(create|lock) folio_lock ext4_mb_init_cache

Засегнати продукти

  • Linux Linux: c9de560ded61faa5b754137b7753da252391c55a преди a3a7d360252c0d84ae8bda067fb296c9e82928d3; c9de560ded61faa5b754137b7753da252391c55a преди 57e83bfbe1e412ac42daced2086f3c6f9a17bba0; c9de560ded61faa5b754137b7753da252391c55a преди c05033cfc5c7699cd4df8d48cef94d01da755f24; c9de560ded61faa5b754137b7753da252391c55a преди 29a07d691d282faf38c33d4b61839b89399110f9; c9de560ded61faa5b754137b7753da252391c55a преди f29709a7a3fc38f5015d850504762cdef0e151f9; c9de560ded61faa5b754137b7753da252391c55a преди bdc56a9c46b2a99c12313122b9352b619a2e719e
  • Linux Linux: 2.6.25; преди 2.6.25; 6.1.191 до 6.1.*; 6.6.130 до 6.6.*; 6.12.75 до 6.12.*; 6.18.14 до 6.18.*; 6.19.4 до 6.19.*; от 7.0 нататък

Вид слабост

История

  • 27 май 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-45942: Linux, състезание за ресурс | freedomonline.bg