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CVE-2026-53264: Linux, грешка в паметта

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.

CVE радар: още уязвимости от този вид

  • Експлоатация: има публичен пример за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: use RCU with deferred freeing for action lifecycle When NEWTFILTER and DELFILTER are run concurrently it is possible to create a race with an associated action. Let's illustrate with CPU0 running NEWTFILTER and CPU1 running DELFILTER: 0: mutex_lock() <-- holds the idr lock 0: rcu_read_lock() 0: p = idr_find(idr, index) <-- action p is valid (RCU protects IDR) 0: mutex_unlock() <-- releases the idr lock 1: refcount_dec_and_mutex_lock() <-- refcnt 1->0, mutex held 1: idr_remove(idr, index) <-- Action removed from IDR 1: mutex_unlock() <-- mutex released allowing us to delete the action 1: tcf_action_cleanup(p); kfree(p) <-- Kfrees p immediately, no deferral 0: refcount_inc_not_zero(&p->tcfa_refcnt) <-- ouch, UAF p points to freed memory This patch fixes the race condition between NEWTFILTER and DELFILTER by adding struct rcu_head to tc_action used in the deferral and introducing a call_rcu() in the delete path to defer the final kfree(). Note: this is a revert of commit d7fb60b9cafb ("net_sched: get rid of tcfa_rcu") but also modernization/simplification to directly use kfree_rcu(). Let's illustrate the new restored code path: 0: rcu_read_lock() 1: refcount_dec_and_mutex_lock() <-- refcnt 1->0, mutex held 1: idr_remove(idr, index) 1: mutex_unlock() 1: call_rcu(&p->tcfa_rcu, tcf_action_rcu_free) <-- defer kfree after grace period 0: p = idr_find(idr, index) 0: refcount_inc_not_zero(&p->tcfa_refcnt) <-- fails, refcnt already 0 1: rcu_read_unlock() <-- release so freeing can run after grace period After CPU1 calls idr_remove(), the object is no longer reachable through the IDR. CPU0's subsequent idr_find() will return NULL, and even if it still held a stale pointer, the immediate kfree() is now deferred until after the RCU grace period, so no UAF can occur.

Засегнати продукти

  • Linux Linux: d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 98b2e40879abf0245be5a5b7af69e0f6ff524ac3; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 18af5d2ef0c4f65787fd1280c8b23286b9f2a835; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 1f1b98fea6b9ea30507d0f2fbff6750292d097e2; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 8b136f18ac4b2ace5aaad3305b3f8a5d8165a009; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 5dd51e09020c65aa53cf128e5e3517cd53b3c113; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди b60e9391142e983fab2be53497aa8f71fdd09cd5; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 91d105d2cbe002f9c7b43a6183adedc37e1da1f7; d7fb60b9cafb982cb2e46a267646a8dfd4f2e5da преди 5057e1aca011e51ef51498c940ef96f3d3e8a305
  • Linux Linux: 4.14; преди 4.14; 5.10.259 до 5.10.*; 5.15.210 до 5.15.*; 6.1.176 до 6.1.*; 6.6.143 до 6.6.*; 6.12.94 до 6.12.*; 6.18.36 до 6.18.*; 7.0.13 до 7.0.*; от 7.1 нататък
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem: всички версии

Вид слабост

История

  • 25 юни 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-53264: Linux, грешка в паметта | freedomonline.bg