Към съдържанието
Търсене

CVE-2026-31711: Linux

7.5

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: smb: server: fix active_num_conn leak on transport allocation failure Commit 77ffbcac4e56 ("smb: server: fix leak of active_num_conn in ksmbd_tcp_new_connection()") addressed the kthread_run() failure path. The earlier alloc_transport() == NULL path in the same function has the same leak, is reachable pre-authentication via any TCP connect to port 445, and was empirically reproduced on UML (ARCH=um, v7.0-rc7): a small number of forced allocation failures were sufficient to put ksmbd into a state where every subsequent connection attempt was rejected for the remainder of the boot. ksmbd_kthread_fn() increments active_num_conn before calling ksmbd_tcp_new_connection() and discards the return value, so when alloc_transport() returns NULL the socket is released and -ENOMEM returned without decrementing the counter. Each such failure permanently consumes one slot from the max_connections pool; once cumulative failures reach the cap, atomic_inc_return() hits the threshold on every subsequent accept and every new connection is rejected. The counter is only reset by module reload. An unauthenticated remote attacker can drive the server toward the memory pressure that makes alloc_transport() fail by holding open connections with large RFC1002 lengths up to MAX_STREAM_PROT_LEN (0x00FFFFFF); natural transient allocation failures on a loaded host produce the same drift more slowly. Mirror the existing rollback pattern in ksmbd_kthread_fn(): on the alloc_transport() failure path, decrement active_num_conn gated on server_conf.max_connections. Repro details: with the patch reverted, forced alloc_transport() NULL returns leaked counter slots and subsequent connection attempts -- including legitimate connects issued after the forced-fail window had closed -- were all rejected with "Limit the maximum number of connections". With this patch applied, the same connect sequence produces no rejections and the c

    Засегнати продукти

    • Linux Linux: 4210c3555db4b38bade92331b153e583261f05f9 преди dc2e7d595d68cf1be1ba64e3d30ebf3266bf7242; d5d7847e57ac69fa99c18b363a34419bcdb5a281 преди 60734c8bc3b4aa0672e251f08dda81977e4b5387; 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 преди 97f8d2648ef4871e4cd335e2d769cb40054a6772; 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 преди 295a9fc6789d1011c36ded9f0f2907bb34fa0de4; 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 преди 283027aa93380380a0994f35dde3ec95318f2654; 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 преди fb48185bcd946d42de7017cf27f912f8ab26acf0; 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 преди 6551300dc452ac16a855a83dbd1e74899542d3b3; 5.15.91 преди 5.15.210; 6.1.9 преди 6.1.175
    • Linux Linux: 6.2; преди 6.2; 5.15.210 до 5.15.*; 6.1.175 до 6.1.*; 6.6.136 до 6.6.*; 6.12.84 до 6.12.*; 6.18.25 до 6.18.*; 7.0.2 до 7.0.*; от 7.1 нататък
    • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem: всички версии

    История

    • 1 май 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-31711: Linux | freedomonline.bg