CVE-2026-53342

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> arm64: mm: call pagetable dtor when freeing hot-removed page tables<br /> <br /> Since 5e8eb9aeeda3 ("arm64: mm: always call PTE/PMD ctor in<br /> __create_pgd_mapping()") page-table allocation on ARM64 always calls<br /> pagetable_{pte,pmd,pud,p4d}_ctor(). This sets the page_type to<br /> PGTY_table, increments NR_PAGETABLE and possible allocates a PTL. However<br /> the matching pagetable_dtor() calls were never added.<br /> <br /> With DEBUG_VM enabled on kernel versions prior to v6.17 without<br /> 2dfcd1608f3a9 ("mm/page_alloc: let page freeing clear any set page type")<br /> this leads to the following warning when freeing these pages due to<br /> page-&gt;page_type sharing page-&gt;_mapcount:<br /> <br /> BUG: Bad page state in process ... pfn:284fbb<br /> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x284fbb<br /> flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff)<br /> page_type: f2(table)<br /> page dumped because: nonzero mapcount<br /> Call trace:<br /> bad_page+0x13c/0x160<br /> __free_frozen_pages+0x6cc/0x860<br /> ___free_pages+0xf4/0x180<br /> free_pages+0x54/0x80<br /> free_hotplug_page_range.part.0+0x58/0x90<br /> free_empty_tables+0x438/0x500<br /> __remove_pgd_mapping.constprop.0+0x60/0xa8<br /> arch_remove_memory+0x48/0x80<br /> try_remove_memory+0x158/0x1d8<br /> offline_and_remove_memory+0x138/0x180<br /> <br /> It can also lead to leaking the ptl allocation if ALLOC_SPLIT_PTLOCKS is<br /> defined and incorrect NR_PAGETABLE stats. Fix this by calling<br /> pagetable_dtor() in free_hotplug_pgtable_page() prior to freeing the page<br /> to undo the effects of calling pagetable_*_ctor().