VULNERABILITY INTELLIGENCE
CVE-2026-52973
Description
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.
Weakness classification
- nvd@nist.gov: CWE-416
- 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-825
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-825
Primary references
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Third Party Advisory
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Issue Tracking, Third Party Advisory
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Third Party Advisory