{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-42126",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc: Avoid nmi_enter/nmi_exit in real mode interrupt.\n\nnmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel\ncrash when invoked during real mode interrupt handling (e.g. early HMI/MCE\ninterrupt handler) if percpu allocation comes from vmalloc area.\n\nEarly HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI()\nwrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when\npercpu allocation is from the embedded first chunk. However with\nCONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu\nallocation can come from the vmalloc area.\n\nWith kernel command line \"percpu_alloc=page\" we can force percpu allocation\nto come from vmalloc area and can see kernel crash in machine_check_early:\n\n[    1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110\n[    1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0\n[    1.215719] --- interrupt: 200\n[    1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable)\n[    1.215722] [c000000fffd731b0] [0000000000000000] 0x0\n[    1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8\n\nFix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu\nfirst chunk is not embedded."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "1da177e4c3f4",
                                            "version_value": "fb6675db04c4"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.10.224",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15.165",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.1.98",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.39",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.9.9",
                                                        "lessThanOrEqual": "6.9.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.10",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848"
            },
            {
                "url": "https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057"
            },
            {
                "url": "https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252"
            },
            {
                "url": "https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e"
            },
            {
                "url": "https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8"
            },
            {
                "url": "https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70"
            }
        ]
    },
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