bpf: Reset register ID for BPF_END value tracking_CVE-2026-43070

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reset register ID for BPF_END value tracking\n\nWhen a register undergoes a BPF_END (byte swap) operation, its scalar\nvalue is mutated in-place. If this register previously shared a scalar ID\nwith another register (e.g., after an `r1 = r0` assignment), this tie must\nbe broken.\n\nCurrently, the verifier misses resetting `dst_reg->id` to 0 for BPF_END.\nConsequently, if a conditional jump checks the swapped register, the\nverifier incorrectly propagates the learned bounds to the linked register,\nleading to false confidence in the linked register's value and potentially\nallowing out-of-bounds memory accesses.\n\nFix this by explicitly resetting `dst_reg->id` to 0 in the BPF_END case\nto break the scalar tie, similar to how BPF_NEG handles it via\n`__mark_reg_known`.",
    "published": "2026-05-05T15:23:28.819Z",
    "modified": "2026-05-08T12:40:19.810Z",
    "type": "cve",
    "title": "bpf: Reset register ID for BPF_END value tracking",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/a17443af874229408ce6b78e2c8a2b5adeb4b7d8\nhttps://git.kernel.org/stable/c/0d15c3611a2cc5d08993545d4032055ae10ae2c1\nhttps://git.kernel.org/stable/c/a3125bc01884431d30d731461634c8295b6f0529",
    "id": "CVE-2026-43070",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 4c03342e5ac532fb34d13a7b51dd7261dfc48963\nLinux Linux d00ce96623a69a100ad79675d0e85fda3c50d89b\nLinux Linux 9d21199842247ab05c675fb9b6c6ca393a5c0024\nLinux Linux 6.18.17\nLinux Linux 6.19.7",
    "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": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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            "privilegesRequired": "",
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            "confidentialityImpact": "",
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            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "4c03342e5ac532fb34d13a7b51dd7261dfc48963",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}