{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-26906",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm: Disallow vsyscall page read for copy_from_kernel_nofault()\n\nWhen trying to use copy_from_kernel_nofault() to read vsyscall page\nthrough a bpf program, the following oops was reported:\n\n  BUG: unable to handle page fault for address: ffffffffff600000\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 3231067 P4D 3231067 PUD 3233067 PMD 3235067 PTE 0\n  Oops: 0000 [#1] PREEMPT SMP PTI\n  CPU: 1 PID: 20390 Comm: test_progs ...... 6.7.0+ #58\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......\n  RIP: 0010:copy_from_kernel_nofault+0x6f/0x110\n  ......\n  Call Trace:\n   <TASK>\n   ? copy_from_kernel_nofault+0x6f/0x110\n   bpf_probe_read_kernel+0x1d/0x50\n   bpf_prog_2061065e56845f08_do_probe_read+0x51/0x8d\n   trace_call_bpf+0xc5/0x1c0\n   perf_call_bpf_enter.isra.0+0x69/0xb0\n   perf_syscall_enter+0x13e/0x200\n   syscall_trace_enter+0x188/0x1c0\n   do_syscall_64+0xb5/0xe0\n   entry_SYSCALL_64_after_hwframe+0x6e/0x76\n   </TASK>\n  ......\n  ---[ end trace 0000000000000000 ]---\n\nThe oops is triggered when:\n\n1) A bpf program uses bpf_probe_read_kernel() to read from the vsyscall\npage and invokes copy_from_kernel_nofault() which in turn calls\n__get_user_asm().\n\n2) Because the vsyscall page address is not readable from kernel space,\na page fault exception is triggered accordingly.\n\n3) handle_page_fault() considers the vsyscall page address as a user\nspace address instead of a kernel space address. This results in the\nfix-up setup by bpf not being applied and a page_fault_oops() is invoked\ndue to SMAP.\n\nConsidering handle_page_fault() has already considered the vsyscall page\naddress as a userspace address, fix the problem by disallowing vsyscall\npage read for copy_from_kernel_nofault()."
            }
        ]
    },
    "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": "6e4694e65b6d"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.10.214",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15.153",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.1.83",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.23",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.7.11",
                                                        "lessThanOrEqual": "6.7.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.8",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
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    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/6e4694e65b6db4c3de125115dd4f55848cc48381",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/6e4694e65b6db4c3de125115dd4f55848cc48381"
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                "url": "https://git.kernel.org/stable/c/e8a67fe34b76a49320b33032228a794f40b0316b",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/e8a67fe34b76a49320b33032228a794f40b0316b"
            },
            {
                "url": "https://git.kernel.org/stable/c/f175de546a3eb77614d94d4c02550181c0a8493e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/f175de546a3eb77614d94d4c02550181c0a8493e"
            },
            {
                "url": "https://git.kernel.org/stable/c/57f78c46f08198e1be08ffe99c4c1ccc12855bf5",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/57f78c46f08198e1be08ffe99c4c1ccc12855bf5"
            },
            {
                "url": "https://git.kernel.org/stable/c/29bd6f86904682adafe9affbc7f79b14defcaff8",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/29bd6f86904682adafe9affbc7f79b14defcaff8"
            },
            {
                "url": "https://git.kernel.org/stable/c/32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58"
            },
            {
                "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html",
                "refsource": "MISC",
                "name": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
            }
        ]
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