# CVE-2026-80776: linux: In the Linux kernel, the following vulnerability has been resolved: futex: Fix race in futex_pivot_pending() during... CVE-2026-80776 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-80776, released September 5, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-80776 - Priority: High - CVSS: n/a (important) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 4, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: futex: Fix race in futex_pivot_pending() during private hash resize A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports: INFO: task futex-resizer:314 blocked for more than 10 seconds. task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311 Call Trace: __schedule+0x521/0xf30 schedule+0x22/0xa0 futex_hash_allocate+0x3db/0x490 __do_sys_prctl+0x6f5/0xbd0 do_syscall_64+0xf9/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: hung_task: blocked tasks futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero. After the final-reference wake, another futex task can complete the pivot between the two observations: T1 T2 futex_hash_allocate() wait_var_event(mm, ...) futex_pivot_pending(mm) hash_new != NULL futex_hash() futex_ref_get(old) -> false futex_pivot_hash(mm) hash_new = NULL __futex_pivot_hash(mm, new) rcu_assign_pointer(hash, new) fph = rcu_dereference(hash) /* new */ futex_ref_is_dead(fph) -> false schedule() The pivot changes the state from hash_new != NULL with a dead current hash to hash_new == NULL with a live current hash. Because futex_pivot_pending() reads hash_new and hash without serialization, the resize task can observe hash_new in the pre-pivot state and hash in the post-pivot state, causing futex_pivot_pending() to return false even though the pivot has completed. The task then goes to sleep after the wakeup has already been consumed. Serialize state reads in futex_pivot_pending() using futex_mm_phash::lock. This guarantees that futex_pivot_pending() observes hash_new and hash atomically, eliminating the race condition. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel-livepatch-6.18.48-107.148 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | linux Debian 14 | 7.1.12-1 | [DEBIAN-CVE-2026-80776](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80776.md) | Sep 5, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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