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CVE-2026-98414: Linux

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CVSS

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Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

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Време до експлоатация

    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: memcg: avoid charging the root memcg from obj_cgroup_charge_pages() obj_cgroup_charge_pages() resolves the objcg to its memcg and calls try_charge_memcg(), which does not short circuit the root memcg. That memcg can be the root memcg: obj_cgroup_is_root() reflects the memcg the objcg was created for and is never updated, while memcg_reparent_objcgs() does redirect objcg->memcg to the parent on rmdir. An objcg of a dying child of root therefore passes every obj_cgroup_is_root() filter but resolves to the root memcg. Folios keep the objcg they were charged with, so this is easy to reach through zswap: allocate anon memory in a cgroup, move the task out, remove the cgroup, then write to the root cgroup's memory.reclaim. The reclaimed folios are charged through the reparented objcg and end up in refill_stock() with the root memcg: WARNING: mm/memcontrol.c:2198 at refill_stock+0x644/0x940 refill_stock+0x644/0x940 try_charge_memcg+0x12d6/0x1570 __obj_cgroup_charge+0x35/0xf0 obj_cgroup_charge+0x1de/0x210 obj_cgroup_charge_zswap+0x83/0x270 zswap_store+0x1620/0x2000 swap_writeout+0x94c/0x14c0 shrink_folio_list+0x3388/0x52b0 [...] try_to_free_mem_cgroup_pages+0x30d/0x830 user_proactive_reclaim+0x504/0x840 memory_reclaim+0x1f/0x30 Beyond the warning, the charge is asymmetric: obj_cgroup_uncharge_pages() skips refill_stock() for the root memcg, so the root's page counter grows and is never uncharged. It is not user visible, since memory.current is not exposed on the root, but it is a leak. Use try_charge(), which returns early for the root memcg, restoring the symmetry with obj_cgroup_uncharge_pages(). The above sequence was scripted into a standalone reproducer (zswap on, swap on a virtio disk, 512MB of anon memory faulted in inside a child of the root cgroup, the task then migrated to the root cgroup, the child removed, followed by "echo 600M swappiness=max > m

    Засегнати продукти

    • Linux Linux: 20d6c17252282c3af261d1cde8e34def1b2458c8 преди d5cdff14c385bf42d03c0dd4c3e88ddf4c28b8a9; 20d6c17252282c3af261d1cde8e34def1b2458c8 преди ecc03877b1b05cb1e3a72175ccb868383eccc518; 20d6c17252282c3af261d1cde8e34def1b2458c8 преди 6e673d0879ef78c395cfe0d3ba316690a60055d8
    • Linux Linux: 6.15; преди 6.15; 6.18.54 до 6.18.*; 7.2.8 до 7.2.*; от 7.3 нататък

    История

    • 14 октомври 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-98414: Linux | freedomonline.bg