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CVE-2026-72422: Linux

9.8

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 по мрежата, без особени условия, без вход и без действие от потребителя.

    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of conn->preauth_info in concurrent SMB2 NEGOTIATE conn->preauth_info is shared connection state (struct preauth_integrity_info, kmalloc-96) that is allocated and freed by the SMB2 NEGOTIATE handler and read by the response send path. smb2_handle_negotiate() allocates conn->preauth_info, and on a deassemble_neg_contexts() failure kfrees it and sets it to NULL. Both the allocation and the free/NULL happen under ksmbd_conn_lock(conn) (the connection srv_mutex), which is held across the whole handler body. The response send path smb3_preauth_hash_rsp(), called from the send: block of __handle_ksmbd_work(), reads conn->preauth_info and dereferences conn->preauth_info->Preauth_HashValue (via ksmbd_gen_preauth_integrity_hash()) without taking conn_lock. When a client drives two SMB2 NEGOTIATE requests on the same connection, one worker can free conn->preauth_info on the failing-negotiate path while a concurrent send-path worker is reading it, producing a slab use-after-free read (KASAN-confirmed). The send-path read tested conn->preauth_info for NULL but raced with the free that occurs between the NULL check and the dereference, so the NULL guard alone does not close the window. Serialize the NEGOTIATE-branch read in smb3_preauth_hash_rsp() under ksmbd_conn_lock(conn) and re-check conn->preauth_info inside the lock. Because the negotiate handler holds conn_lock across its kfree + NULL assignment, a reader that also takes conn_lock either runs fully before the allocation or fully after the NULL store, and can never observe the freed-but-not-yet-NULLed pointer. ksmbd_gen_preauth_integrity_hash() takes no locks itself (it only computes a SHA-512 over the buffer), so no lock-ordering inversion is introduced, and conn_lock is a sleepable mutex which is safe on this send path (it already performs network I/O).

    Засегнати продукти

    • Linux Linux: dd4e4c811898410e6a3ae3b63207b7c542860907 преди c7bef84740d1d57848c74f6f5b996606e43ea4fe; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди d0a469122e7bf8338fec1949fb1e8e1290ed8caa; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди 7470511d085af1c7a043a60e53d52b512d5a10b1; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди 16a1ecf39c217e3d164bd32ef2a4f650abc067fa; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди 77bb0bbfcc4e777ca653174689e5e363f8ee63d1; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди 1c89da3baa2b1f269178afa87dc30479b8535776; aa7253c2393f6dcd6a1468b0792f6da76edad917 преди 0c054227479ed7e36ebccb3a558bc0ef698264f6; 8a8315a5960bd2b5ffc75f44fc089e57c3b17c44; ff20f1875889dbe4a67c9298e609d7c88cf6456d; 5.15.61 преди 5.15.212; 5.18.18 преди 5.19; 5.19.2 преди 5.20
    • Linux Linux: 6.0; преди 6.0; 5.15.212 до 5.15.*; 6.1.178 до 6.1.*; 6.6.145 до 6.6.*; 6.12.97 до 6.12.*; 6.18.40 до 6.18.*; 7.1.5 до 7.1.*; 7.2 до *

    История

    • 15 август 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-72422: Linux | freedomonline.bg