Linux kernel rtmutex remove_waiter() use-after-free risk
CVE-2026-43499 is a Linux kernel rtmutex flaw in remove_waiter(). The bug arises because remove_waiter() used current for waiter dequeue and related operations, even though the function is also invoked during proxy-lock rollback in rt_mutex_start_proxy_lock() from futex_requeue(), where waiter::task is not necessarily current. As a result, the code can perform the rbtree dequeue without holding the correct waiter task's pi_lock, fail to clear the waiter task's pi_blocked_on state, and drive rt_mutex_adjust_prio_chain() using the wrong top-priority waiter task. The stale pi_blocked_on reference leaves a dangling pointer condition that is primed for use-after-free.
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Recent activity
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Referenced as one of many vulnerabilities solved by SUSE security updates; no technical details provided in the content.
A specific vulnerability identified as CVE-2026-43499 is referenced in the context of initial exploit code and a writeup being created, indicating security research or exploit development activity.
A Linux kernel rtmutex flaw in remove_waiter() where current was used instead of waiter::task during dequeue and related operations, causing improper locking, uncleared pi_blocked_on state, dangling pointer/UAF risk, and incorrect priority-chain adjustment.
Linux kernel rtmutex vulnerability involving incorrect task reference handling in waiter removal.
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Cross-references every affected SKU, including bundled OEM variants.
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