CVE-2024-35993
Published: May 21, 2024Last modified: May 21, 2024
Description
In the Linux kernel, the following vulnerability has been resolved: mm: turn folio_test_hugetlb into a PageType The current folio_test_hugetlb() can be fooled by a concurrent folio split into returning true for a folio which has never belonged to hugetlbfs. This can't happen if the caller holds a refcount on it, but we have a few places (memory-failure, compaction, procfs) which do not and should not take a speculative reference. Since hugetlb pages do not use individual page mapcounts (they are always fully mapped and use the entire_mapcount field to record the number of mappings), the PageType field is available now that page_mapcount() ignores the value in this field. In compaction and with CONFIG_DEBUG_VM enabled, the current implementation can result in an oops, as reported by Luis. This happens since 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") effectively added some VM_BUG_ON() checks in the PageHuge() testing path. [[email protected]: update vmcoreinfo] Link: https://lkml.kernel.org/r/[email protected]
Status
Product | Release | Package | Status |
---|---|---|---|
Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.33-r0) |
Stream | linux-lts | Fixed (6.6.58-r0) |