CVE-2026-52973

In the Linux kernel, the following vulnerability has been resolved: futex: Drop CLONE_THREAD requirement for private default hash alloc Currently need_futex_hash_allocate_default() depends on strict pthread semantics, abusing CLONE_THREAD. This breaks the non-concurrency assumptions when doing the mm->futex_ref pcpu allocations, leading to bugs[0] when sharing the mm in other ways; ie: BUG: KASAN: slab-use-after-free in futex_hash_put ... where the +1 bias can end up on a percpu counter that mm->futex_ref no longer points at. Loosen the check to cover any CLONE_VM clone, except vfork(). Excluding vfork keeps the existing paths untouched (no overhead), and we can't race in the first place: either the parent is suspended and the child runs alone, or mm->futex_ref is already allocated from an earlier CLONE_VM.

CVSS 3.1

7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 7% of CVEs (scores of 2026-10-25)

CWEs

CWE-416, CWE-825

Published

2026-06-24

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d
• https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091
• https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a
• https://access.redhat.com/errata/RHSA-2026:45114
• https://access.redhat.com/errata/RHSA-2026:47040

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