bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops_CVE-2026-53078

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix same-register dst/src OOB read and pointer leak in sock_ops\n\nWhen a BPF sock_ops program accesses ctx fields with dst_reg == src_reg,\nthe SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the\ndestination register in the !fullsock / !locked_tcp_sock path.\n\nBoth macros borrow a temporary register to check is_fullsock /\nis_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the\nctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with\na request_sock), dst_reg should be zeroed but is not, leaving the stale\nctx pointer:\n\n - SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks\n   as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer,\n   leading to stack-out-of-bounds access in helpers like\n   bpf_skc_to_tcp6_sock().\n\n - SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the\n   verifier believes is a SCALAR_VALUE, leaking a kernel pointer.\n\nFix both macros by:\n - Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the\n   added instruction.\n - Adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register\n   restore in the !fullsock path, placed after the restore because\n   dst_reg == src_reg means we need src_reg intact to read ctx->temp.",
    "published": "2026-06-24T16:30:18.858Z",
    "modified": "2026-06-28T06:39:04.474Z",
    "type": "cve",
    "title": "bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/18e3ffde1822f0b48b1753bf34aa97ce839df1d8\nhttps://git.kernel.org/stable/c/10f86a2a5c91fc4c4d001960f1c21abe52545ef6",
    "id": "CVE-2026-53078",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux fd09af010788a884de1c39537c288830c3d305db\nLinux Linux fd09af010788a884de1c39537c288830c3d305db\nLinux Linux 48be3df15aa19c04eadf156c9129293c9a10389f\nLinux Linux cd4644d904e1d153d516e73e2e127e7a2fe687e1\nLinux Linux 6e0bc946cbeec538322820786b5fb5200a2216ab\nLinux Linux a7e52f7f675046d9ffc5692d815fa67c82fcdbf5\nLinux Linux db7f8c57dbdd31f7e59f8dc8d1e1b38607a320ef\nLinux Linux 5.7.18\nLinux Linux 5.8.4\nLinux Linux 5.4.61\nLinux Linux 5.9",
    "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": "",
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            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "fd09af010788a884de1c39537c288830c3d305db",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
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    "ai_score": 0
}