CVE-2026-80778
In the Linux kernel, the following vulnerability has been resolved: futex/pi: Reject cross-mm private futex owners A private futex key borrows the waiter's mm without taking an mm_users reference. Nevertheless, attach_to_pi_owner() currently accepts an owner from a different address space and copies the private key into the owner's PI state. When that owner exits, exit_pi_state_list() uses the saved key to find the hash bucket and acquires a reference to the waiter's private hash. If the last user of the waiter's mm exits concurrently, futex_hash_free() frees the hash while the owner still uses its bucket and reference. Prevent this by validating in attach_to_pi_owner() that, for private futexes, the owner mm and waiter mm are the same. Perform the check with the owner's pi_lock held and after validating owner::futex::state to serialize against a concurrent PI-state exit cleanup. [ tglx: Amended comment ]
Affected versions
Linux kernel versions
6.16
and later are affected. Fixed in
6.18.47,
7.1.11,
7.2.1,
7.3
and their respective stable series.
References
4 totalFrequently asked questions
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What is CVE-2026-80778?
CVE-2026-80778 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.16 onward and has been patched in 6.18.47, 7.1.11, 7.2.1 and others. CVE-2026-80778 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-80778?
Yes. CVE-2026-80778 has been patched. Fixed versions include 6.18.47, 7.1.11, 7.2.1 and others. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-80778 actively exploited?
No. CVE-2026-80778 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.