rtmutex: Use waiter::task instead of current in remove_waiter()

In the Linux kernel, the following vulnerability has been resolved: r ...

In the Linux kernel, the following vulnerability has been resolved: futex/requeue: Prevent NULL pointer dereference in remove_waiter() on self-deadlock When FUTEX_CMP_REQUEUE_PI requeues a non-top waiter that already owns the target PI futex, task_blocks_on_rt_mutex() returns -EDEADLK before setting waiter->task. The subsequent remove_waiter() in rt_mutex_start_proxy_lock() dereferences the NULL waiter->task, causing a kernel crash. Add a self-deadlock check for non-top waiters before calling rt_mutex_start_proxy_lock(), analogous to the top-waiter check in futex_lock_pi_atomic().

Уязвимость функции futex_requeue() модуля kernel/futex/requeue.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

ELSA-2026-50388: Unbreakable Enterprise kernel security update (IMPORTANT)

ELSA-2026-50387: Unbreakable Enterprise kernel security update (IMPORTANT)

Уязвимость функций remove_waiter(), futex_requeue(), rt_mutex_adjust_prio_chain() ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации

Уязвимость kernel-lt

Уязвимость kernel-lt

Important: kernel security update

ELSA-2026-19568: kernel security update (IMPORTANT)

Important: kernel security update

ELSA-2026-21706: kernel security update (IMPORTANT)

ELSA-2026-500121: Unbreakable Enterprise kernel security update (IMPORTANT)

Security update for the Linux Kernel

Security update for the Linux Kernel

ELSA-2026-50319: Unbreakable Enterprise kernel security update (IMPORTANT)

Security update for the Linux Kernel

ELSA-2026-50372: Unbreakable Enterprise kernel security update (IMPORTANT)