futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()_CVE-2026-23415

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma->vm_policy is read under\nspeculative mmap lock and RCU. Concurrently, mbind() may call\nvma_replace_policy() which frees the old mempolicy immediately via\nkmem_cache_free().\n\nThis creates a race where __futex_key_to_node() dereferences a freed\nmempolicy pointer, causing a use-after-free read of mpol->mode.\n\n[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)\n[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87\n\n[  151.415969] Call Trace:\n\n[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)\n[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)\n[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)\n\nFix by adding rcu to __mpol_put().",
    "published": "2026-04-02T11:40:56.476Z",
    "modified": "2026-04-27T14:02:14.037Z",
    "type": "cve",
    "title": "futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0\nhttps://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe\nhttps://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa",
    "id": "CVE-2026-23415",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux c042c505210dc3453f378df432c10fff3d471bc5\nLinux Linux c042c505210dc3453f378df432c10fff3d471bc5\nLinux Linux c042c505210dc3453f378df432c10fff3d471bc5\nLinux Linux 6.16",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
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            "privilegesRequired": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "c042c505210dc3453f378df432c10fff3d471bc5",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}