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CVE-2026-74714: 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.

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: bpf: tcp: Fix use-after-free in bpf_iter_tcp_established_batch() reqsk_queue_hash_req() publishes a TCP_NEW_SYN_RECV request_sock onto the ehash chain, drops the bucket lock, and only afterwards sets rsk_refcnt to 3. Lockless readers such as __inet_lookup_established() handle this with refcount_inc_not_zero(), but bpf_iter_tcp_established_batch() uses plain sock_hold() while holding the bucket lock, on the assumption that the lock guarantees sk_refcnt > 0. That assumption does not hold for request_sock: CPU 0 CPU 1 ----- ----- tcp_conn_request() reqsk_queue_hash_req() inet_ehash_insert(req) spin_lock(bucket) __sk_nulls_add_node_rcu(req) // rsk_refcnt == 0 spin_unlock(bucket) bpf_iter_tcp_established_batch() spin_lock(bucket) sock_hold(req) <-- addition on 0 spin_unlock(bucket) refcount_set(&req->rsk_refcnt, 3) // clobbers saturated value which surfaces as: refcount_t: addition on 0; use-after-free. WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x48/0x90, CPU#1 Call Trace: bpf_iter_tcp_established_batch+0x14e/0x170 bpf_iter_tcp_batch+0x53/0x200 bpf_iter_tcp_seq_next+0x27/0x70 bpf_seq_read+0x107/0x410 vfs_read+0xb9/0x380 The iterator's stolen reference is lost when the publishing CPU's refcount_set() overwrites the count, leaving the socket one reference short. When the last legitimate owner drops its reference the reqsk is freed while still reachable, leading to use-after-free. This reproduces in seconds with tcp_syncookies=0, a handful of threads doing connect()/close() to a local listener while others read an iter/tcp link in a tight loop. Use refcount_inc_not_zero() and skip the socket on failure. A skipp

Засегнати продукти

  • Linux Linux: 04c7820b776f1c4b48698574c47de9e940d368e8 преди cc0295f89296ed351fc4b0b48fee887ba02c5d24; 04c7820b776f1c4b48698574c47de9e940d368e8 преди ddbe966b5d1fe212ada749bc3d0b410f1a7dea74; 04c7820b776f1c4b48698574c47de9e940d368e8 преди 7d2b60a4bc0499f62ff8520af6309bbe170882fd; 04c7820b776f1c4b48698574c47de9e940d368e8 преди cefcbbe20846a45f9a7dae868f7ef1000953e2df; 04c7820b776f1c4b48698574c47de9e940d368e8 преди 97e74d3e45d653c07c2d406fc530a9bbe3df8396; 04c7820b776f1c4b48698574c47de9e940d368e8 преди e5fd3f514e27db1f05fbd72ba615d74941e23c51
  • Linux Linux: 5.15; преди 5.15; 6.1.183 до 6.1.*; 6.6.152 до 6.6.*; 6.12.104 до 6.12.*; 6.18.45 до 6.18.*; 7.1.9 до 7.1.*; от 7.2 нататък

История

  • 22 август 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-74714: Linux | freedomonline.bg