CVE-2026-43499
HIGH
CVSS 7.8
No EPSS data
Description
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 ]
CVSS details
EPSS
This CVE is not currently listed in the EPSS dataset.
Show JSON
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtmutex: Use waiter::task instead of current in remove_waiter()\n\nremove_waiter() is used by the slowlock paths, but it is also used for\nproxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from\nfutex_requeue().\n\nIn the latter case waiter::task is not current, but remove_waiter()\noperates on current for the dequeue operation. That results in several\nproblems:\n\n 1) the rbtree dequeue happens without waiter::task::pi_lock being held\n\n 2) the waiter task's pi_blocked_on state is not cleared, which leaves a\n dangling pointer primed for UAF around.\n\n 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter\n task\n\nUse waiter::task instead of current in all related operations in\nremove_waiter() to cure those problems.\n\n[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the\n \tchangelog ]"
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"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nrtmutex: Usar waiter::task en lugar de current en remove_waiter()\n\nremove_waiter() es usado por las rutas de slowlock, pero tambi\u00e9n es usado para la reversi\u00f3n de bloqueo de proxy en rt_mutex_start_proxy_lock() cuando es invocado desde futex_requeue().\n\nEn este \u00faltimo caso, waiter::task no es current, pero remove_waiter() opera en current para la operaci\u00f3n de desencolado. Eso resulta en varios problemas:\n\n 1) el desencolado de rbtree ocurre sin que waiter::task::pi_lock est\u00e9 retenido\n\n 2) el estado pi_blocked_on de la tarea de espera no se borra, lo que deja un puntero colgante preparado para UAF.\n\n 3) rt_mutex_adjust_prio_chain() opera en la tarea de espera de m\u00e1xima prioridad incorrecta\n\nUsar waiter::task en lugar de current en todas las operaciones relacionadas en remove_waiter() para solucionar esos problemas.\n\n[ tglx: Corregir rt_mutex_adjust_prio_chain(), a\u00f1adir un comentario y modificar el registro de cambios ]"
}
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