Към съдържанието

CVE-2026-93250: 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: vxlan: mdb: Fix use-after-free in vxlan_mdb_flush() vxlan_mdb_flush() iterates over the MDB entries using hlist_for_each_entry_safe(), which only tolerates the removal of the current entry. Contrary to the comment above the loop, the removal of an entry can trigger the removal of another entry. Flushing the remotes of a (*, G) entry also removes the (S, G) entries that were created for its source list, once they are left without remotes: vxlan_mdb_remotes_flush() -> vxlan_mdb_remote_del() -> vxlan_mdb_remote_srcs_del() -> vxlan_mdb_remote_src_del() -> vxlan_mdb_remote_src_fwd_del() -> __vxlan_mdb_del() -> vxlan_mdb_entry_put() Such an entry can be located after the (*, G) entry in the list, as vxlan_mdb_entry_get() returns an existing entry without moving it to the head of the list. This order is obtained by adding the (S, G) entry before the (*, G) entry, the latter with NLM_F_REPLACE, as the addition of the source otherwise fails with -EEXIST. The (S, G) entry is then the entry saved by hlist_for_each_entry_safe() and it is freed while the (*, G) entry is processed. The next iteration calls hlist_del() on it again, writing LIST_POISON1 to LIST_POISON2 [1]. Besides device deletion, the flush is also reachable from RTM_DELMDB with NLM_F_BULK. Fix by re-reading the next entry after the remotes were flushed. The current entry cannot be removed by this flush, as source lists can only be configured on (*, G) entries and the removed entries are (S, G) entries. It is therefore still linked and its next pointer reflects the removals. [1] BUG: KASAN: wild-memory-access in vxlan_mdb_entry_put.part.0+0x328/0x588 Write of size 8 at addr dead000000000122 by task ip/327 CPU: 3 UID: 1000 PID: 327 Comm: ip Not tainted 7.2.0-rc7 #2 PREEMPT Call trace: vxlan_mdb_entry_put.part.0+0x328/0x588 vxlan_mdb_flush+0x1d8/0x25c vxlan_mdb_fini+0x8c/0x100 vxlan_uninit+0x

    Засегнати продукти

    • Linux Linux: a3a48de5eade770e911d35291217bdd69ce04ef1 преди f8a9b988e7a7bc674e74e8c901794d792c35689e; a3a48de5eade770e911d35291217bdd69ce04ef1 преди c7dc26d06f90ca11bbd6114f6a62a67d038816c7; a3a48de5eade770e911d35291217bdd69ce04ef1 преди 3e6b705bc162fc7257645725a7d2cf6c71250318; a3a48de5eade770e911d35291217bdd69ce04ef1 преди f26400b325bdc2868e40612c4804c82cf8ba6275; a3a48de5eade770e911d35291217bdd69ce04ef1 преди bc2dc66a6693a78f8c1e6ca2dbebd50f16e2c366
    • Linux Linux: 6.4; преди 6.4; 6.6.157 до 6.6.*; 6.12.110 до 6.12.*; 6.18.52 до 6.18.*; 7.2.6 до 7.2.*; от 7.3 нататък

    История

    • 24 септември 2026 Публикувано

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