{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-26674",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/lib: Revert to _ASM_EXTABLE_UA() for {get,put}_user() fixups\n\nDuring memory error injection test on kernels >= v6.4, the kernel panics\nlike below. However, this issue couldn't be reproduced on kernels <= v6.3.\n\n  mce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134\n  mce: [Hardware Error]: RIP 10:<ffffffff821b9776> {__get_user_nocheck_4+0x6/0x20}\n  mce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86\n  mce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490\n  mce: [Hardware Error]: Run the above through 'mcelog --ascii'\n  mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel\n  Kernel panic - not syncing: Fatal local machine check\n\nThe MCA code can recover from an in-kernel #MC if the fixup type is\nEX_TYPE_UACCESS, explicitly indicating that the kernel is attempting to\naccess userspace memory. However, if the fixup type is EX_TYPE_DEFAULT\nthe only thing that is raised for an in-kernel #MC is a panic.\n\nex_handler_uaccess() would warn if users gave a non-canonical addresses\n(with bit 63 clear) to {get, put}_user(), which was unexpected.\n\nTherefore, commit\n\n  b19b74bc99b1 (\"x86/mm: Rework address range check in get_user() and put_user()\")\n\nreplaced _ASM_EXTABLE_UA() with _ASM_EXTABLE() for {get, put}_user()\nfixups. However, the new fixup type EX_TYPE_DEFAULT results in a panic.\n\nCommit\n\n  6014bc27561f (\"x86-64: make access_ok() independent of LAM\")\n\nadded the check gp_fault_address_ok() right before the WARN_ONCE() in\nex_handler_uaccess() to not warn about non-canonical user addresses due\nto LAM.\n\nWith that in place, revert back to _ASM_EXTABLE_UA() for {get,put}_user()\nexception fixups in order to be able to handle in-kernel MCEs correctly\nagain.\n\n  [ bp: Massage commit message. ]"
            }
        ]
    },
    "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": "b19b74bc99b1",
                                            "version_value": "2aed1b6c33af"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.4",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.4",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.17",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.7.5",
                                                        "lessThanOrEqual": "6.7.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.8",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/2aed1b6c33afd8599d01c6532bbecb829480a674",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/2aed1b6c33afd8599d01c6532bbecb829480a674"
            },
            {
                "url": "https://git.kernel.org/stable/c/2da241c5ed78d0978228a1150735539fe1a60eca",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/2da241c5ed78d0978228a1150735539fe1a60eca"
            },
            {
                "url": "https://git.kernel.org/stable/c/8eed4e00a370b37b4e5985ed983dccedd555ea9d",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8eed4e00a370b37b4e5985ed983dccedd555ea9d"
            }
        ]
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    "generator": {
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}