{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "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()."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/x86/mm/maccess.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "6e4694e65b6d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "e8a67fe34b76",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "f175de546a3e",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "57f78c46f081",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "29bd6f869046",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "32019c659ecf",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/x86/mm/maccess.c"
               ],
               "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"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/6e4694e65b6db4c3de125115dd4f55848cc48381"
            },
            {
               "url": "https://git.kernel.org/stable/c/e8a67fe34b76a49320b33032228a794f40b0316b"
            },
            {
               "url": "https://git.kernel.org/stable/c/f175de546a3eb77614d94d4c02550181c0a8493e"
            },
            {
               "url": "https://git.kernel.org/stable/c/57f78c46f08198e1be08ffe99c4c1ccc12855bf5"
            },
            {
               "url": "https://git.kernel.org/stable/c/29bd6f86904682adafe9affbc7f79b14defcaff8"
            },
            {
               "url": "https://git.kernel.org/stable/c/32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58"
            }
         ],
         "title": "x86/mm: Disallow vsyscall page read for copy_from_kernel_nofault()",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-26906",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}