{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-93111",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-17T16:02:15.086Z",
        "datePublished": "2026-09-17T16:11:20.464Z",
        "dateUpdated": "2026-10-19T09:05:44.850Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T09:05:44.850Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Mark tracing_multi trampolines as ftrace managed\n\nSince tracing_multi link does not set ftrace_managed, it would fail to\nrelease the tracing_multi link when attaching tracing_multi link and\nthen attaching fentry link.\n\n[    3.714215] WARNING: kernel/bpf/trampoline.c:1727 at bpf_trampoline_multi_detach+0x20b/0x240, CPU#1: test_progs/97\n...\n[    3.733170]  bpf_tracing_multi_link_release+0x14/0x30\n[    3.733890]  bpf_link_free+0x58/0x130\n[    3.734414]  bpf_link_release+0x23/0x30\n\nFix it by setting 'ftrace_managed = true' in register_fentry_multi()."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - Reached only via local bpf(2): BPF_PROG_LOAD of BPF_TRACE_FENTRY_MULTI then BPF_LINK_CREATE → link_create() → bpf_tracing_multi_attach() → register_fentry_multi(), then a regular BPF_TRACE_FENTRY BPF_LINK_CREATE through bpf_tracing_prog_attach(). The trigger is that attach order, not a remote protocol message.\nAC:L - The attacker chooses the order: tracing_multi first so register_fentry_multi() never sets tr->func.ftrace_managed, then fentry so modify_fentry() takes bpf_arch_text_poke() instead of direct_ops_mod(), then close() of the tracing_multi fd into bpf_trampoline_multi_detach(). No race or uninfluenced victim state is required.\nPR:L - bpf_prog_load() for BPF_PROG_TYPE_TRACING (fentry.multi and fentry) requires bpf_token_capable(CAP_BPF) and, via is_perfmon_prog_type(), bpf_token_capable(CAP_PERFMON). Those caps are delegable with a BPF token into a non-init user namespace, so this is Low rather than init-namespace root.\nUI:N - The attacker loads both programs, creates the tracing_multi and fentry links, and closes the tracing_multi fd themselves (bpf_link_release → bpf_tracing_multi_link_release). No other user must mount, open, or otherwise act on attacker-supplied objects.\nS:U - The use-after-free is of a kernel bpf_tramp_image that remains an ftrace direct-call target. That is in-kernel privilege escalation, not a KVM/Xen guest-to-host or IOMMU boundary cross, so scope stays Unchanged.\nC:H - modify_fentry() text-pokes the fentry site to Image B and bpf_tramp_image_put()s Image A; bpf_trampoline_multi_detach() still bpf_tramp_image_put()s Image B in bpf_trampoline_multi_attach_free() after update_ftrace_direct_del/mod fails, so a later call of the hooked function executes freed trampoline memory.\nI:H - The hooked function’s live CALL/JMP still targets the trampoline image bpf_trampoline_multi_attach_free() freed after the failed ftrace update, so reclaiming that JIT page hijacks control flow at the ftrace site (arbitrary kernel write/execute).\nA:H - bpf_trampoline_multi_detach() hits WARN_ON_ONCE(update_ftrace_direct_del()) at trampoline.c:1727 when ftrace’s recorded direct target no longer matches the poked site, and the subsequent jump into the freed bpf_tramp_image oopses or panics."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/trampoline.c"
                    ],
                    "versions": [
                        {
                            "version": "aef4dfa790b22d8052cfb78044eadbe03c876c39",
                            "lessThan": "280145253fd38fa975cc04963ddaf74c7f415011",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "aef4dfa790b22d8052cfb78044eadbe03c876c39",
                            "lessThan": "30bdd6d1384d894931f113eb595636092d8e650c",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/trampoline.c"
                    ],
                    "versions": [
                        {
                            "version": "7.2",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.2",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.6",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.2",
                                    "versionEndExcluding": "7.2.6"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.2",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/280145253fd38fa975cc04963ddaf74c7f415011"
                },
                {
                    "url": "https://git.kernel.org/stable/c/30bdd6d1384d894931f113eb595636092d8e650c"
                }
            ],
            "title": "bpf: Mark tracing_multi trampolines as ftrace managed",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}