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CVE-2026-74513: Linux

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.

    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: dibs: fix use-after-free of dmb_node in loopback attach/detach/unregister dibs_lo_attach_dmb(), dibs_lo_detach_dmb() and dibs_lo_unregister_dmb() look up the dmb_node under dmb_ht_lock, drop the lock and only then operate on the node's refcount. Nothing keeps the node alive across that window: __dibs_lo_unregister_dmb() removes the node from the hash table under the write lock and immediately frees it. A concurrent final put can therefore free the node between the lookup and the refcount operation: CPU0 (attach) CPU1 (owner unregisters) read_lock_bh(&dmb_ht_lock) find dmb_node (refcnt == 1) read_unlock_bh(&dmb_ht_lock) refcount_dec_and_test() 1 -> 0 write_lock_bh(&dmb_ht_lock) hash_del(&dmb_node->list) write_unlock_bh(&dmb_ht_lock) kfree(dmb_node) refcount_inc_not_zero(&dmb_node->refcnt) <-- use-after-free The same window exists for the refcount_dec_and_test() calls in the detach and unregister paths. Close the race structurally by making hash table membership and the refcount transitions atomic with respect to each other: - Perform the final refcount_dec_and_test() and hash_del() in a single dmb_ht_lock write-side critical section, in both the unregister and the detach path. Freeing the node still happens after the lock is dropped, which is safe because a node whose refcount reached zero has left the hash table and can no longer be found. - This establishes the invariant that any node found in the hash table holds at least one reference, and that the final reference can only be dropped under the write lock. dibs_lo_attach_dmb() can thus take its reference with a plain refcount_inc() while still holding the read lock; refcount_inc_not_zero() is no longer needed. __dibs_lo_unregister_dmb

    Засегнати продукти

    • Linux Linux: c3a910f2380fe294d14e42af66af3d3eed8fecbf преди 90b2166605a7476007f7c013521d30b0be557cac; c3a910f2380fe294d14e42af66af3d3eed8fecbf преди c0837aeace96152d14b17fdd19d70102b6631a7d; c3a910f2380fe294d14e42af66af3d3eed8fecbf преди 48c073f88c93707089a4214f21cb4c3de5aea6e4; c3a910f2380fe294d14e42af66af3d3eed8fecbf преди a10ea943356b9d70c5616a0a06f6fa97cfdaccb1
    • Linux Linux: 6.10; преди 6.10; 6.12.114 до 6.12.*; 6.18.44 до 6.18.*; 7.1.8 до 7.1.*; 7.2 до *

    История

    • 15 август 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-74513: Linux | freedomonline.bg