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Description

In the Linux kernel, the following vulnerability has been resolved: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free(). This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode. [ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87 [ 151.415969] Call Trace: [ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593) Fix by adding rcu to __mpol_put().

PUBLISHED Reserved 2026-01-13 | Published 2026-04-02 | Updated 2026-05-11 | Assigner Linux




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

Product status

Default status
unaffected

c042c505210dc3453f378df432c10fff3d471bc5 (git) before 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0
affected

c042c505210dc3453f378df432c10fff3d471bc5 (git) before 7e196194ea27bd49adf3551e2aceb83498eb73fe
affected

c042c505210dc3453f378df432c10fff3d471bc5 (git) before 190a8c48ff623c3d67cb295b4536a660db2012aa
affected

Default status
affected

6.16
affected

Any version before 6.16
unaffected

6.18.21 (semver)
unaffected

6.19.11 (semver)
unaffected

7.0 (original_commit_for_fix)
unaffected

References

git.kernel.org/...c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0

git.kernel.org/...c/7e196194ea27bd49adf3551e2aceb83498eb73fe

git.kernel.org/...c/190a8c48ff623c3d67cb295b4536a660db2012aa

cve.org (CVE-2026-23415)

nvd.nist.gov (CVE-2026-23415)

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