xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()_CVE-2026-53239

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\n\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it. Use __xfrm_policy_inexact_prune_bin() directly since\nthe lock is already held. The wrapper xfrm_policy_inexact_prune_bin()\nbecomes unused and is removed.\n\nRace:\n\n  CPU0 (XFRM_MSG_DELPOLICY)           CPU1 (XFRM_MSG_NEWSPDINFO)\n  ==========================          ==========================\n  xfrm_policy_bysel_ctx():\n    spin_lock_bh(xfrm_policy_lock)\n    bin = xfrm_policy_inexact_lookup()\n    __xfrm_policy_unlink(pol)\n    spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_kill(ret)\n    // wide window, lock not held\n                                       xfrm_hash_rebuild():\n                                         spin_lock_bh(xfrm_policy_lock)\n                                         __xfrm_policy_inexact_flush():\n                                           kfree_rcu(bin)  // bin freed\n                                         spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_inexact_prune_bin(bin)\n    // UAF: bin is freed",
    "published": "2026-06-25T08:39:35.149Z",
    "modified": "2026-06-28T06:40:46.548Z",
    "type": "cve",
    "title": "xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/8fc536e9f6856230f19c7d13e71af064b6a77b22\nhttps://git.kernel.org/stable/c/c4c1ea36d83bf3c4569468ca5b8b614fda1bf821\nhttps://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7\nhttps://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121c\nhttps://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0f\nhttps://git.kernel.org/stable/c/b5316e2b8614a87d8736941972441cb47bfd4491\nhttps://git.kernel.org/stable/c/ec82ea4eb220164d854f8734ca5a35e23e577b94\nhttps://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60",
    "id": "CVE-2026-53239",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 6be3b0db6db82cf056a72cc18042048edd27f8ee\nLinux Linux 5.0",
    "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": {
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        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "6be3b0db6db82cf056a72cc18042048edd27f8ee",
    "vendor": "Linux",
    "ai_description": "",
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    "ai_score": 0
}