{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/kernel/smp.c",
            "include/linux/compiler_attributes.h",
            "init/main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "25e73018b4093e0cfbcec5dc4a4bb86d0b69ed56",
              "status": "affected",
              "version": "420594296838fdc9a674470d710cda7d1487f9f4",
              "versionType": "git"
            },
            {
              "lessThan": "514ca14ed5444b911de59ed3381dfd195d99fe4b",
              "status": "affected",
              "version": "420594296838fdc9a674470d710cda7d1487f9f4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/kernel/smp.c",
            "include/linux/compiler_attributes.h",
            "init/main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.30"
            },
            {
              "lessThan": "2.6.30",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.4.*",
              "status": "unaffected",
              "version": "6.4.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.5",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.4.4",
                  "versionStartIncluding": "2.6.30",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.5",
                  "versionStartIncluding": "2.6.30",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nstart_kernel: Add __no_stack_protector function attribute\n\nBack during the discussion of\ncommit a9a3ed1eff36 (\"x86: Fix early boot crash on gcc-10, third try\")\nwe discussed the need for a function attribute to control the omission\nof stack protectors on a per-function basis; at the time Clang had\nsupport for no_stack_protector but GCC did not. This was fixed in\ngcc-11. Now that the function attribute is available, let\u0027s start using\nit.\n\nCallers of boot_init_stack_canary need to use this function attribute\nunless they\u0027re compiled with -fno-stack-protector, otherwise the canary\nstored in the stack slot of the caller will differ upon the call to\nboot_init_stack_canary. This will lead to a call to __stack_chk_fail()\nthen panic."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - There is no network-reachable path to this code \u2014 `start_kernel()` and powerpc `start_secondary()` are kernel-initialization and CPU-bring-up entry points invoked from architecture assembly (`head_64.S`, `head_44x.S`, `head_85xx.S`) and from `__cpu_up()` during hotplug/resume, all of which are local to the machine. The vulnerable component is therefore only reachable via local system context (boot, CPU hotplug, suspend/resume).\nAC:L - On a kernel built with `CONFIG_STACKPROTECTOR=y` and a toolchain that instruments these functions, the stale-canary comparison mismatches deterministically on every boot and every secondary-CPU bring-up \u2014 there is no race, no memory-layout dependency, and no timing window to win. The failure reproduces reliably and at will, so no condition beyond the attacker\u0027s control gates it.\nPR:N - The panic in `start_kernel()` occurs during kernel initialization, before `init(1)` and before any user account, credential check, or namespace exists; the `start_secondary()` path is likewise entered from the secondary-CPU assembly stub with no privilege gate. No authentication or privilege of any kind is involved in reaching the faulty canary check.\nUI:N - No victim action is needed \u2014 the condition is hit automatically as part of normal boot and CPU bring-up. Nothing must be mounted, opened, or clicked.\nS:U - The `__stack_chk_fail()` \u2192 `panic()` sequence is entirely contained within the kernel\u0027s own security authority, affecting only the kernel that executed it. No VM, IOMMU, or sandbox boundary is crossed.\nC:N - `__stack_chk_fail()` is a fail-stop check: it halts the system rather than reading or exposing memory, and no out-of-bounds read, uninitialized data, or attacker-retrievable kernel state is produced. Per the pure-crash guidance, there is no information disclosure.\nI:N - Nothing is written out of bounds and no object is corrupted \u2014 the canary in the caller\u0027s frame is intact; the comparison is a false positive caused by the canary *source* changing underneath it. There is no write primitive and no control-flow hijack potential.\nA:H - The outcome is `panic(\"stack-protector: Kernel stack is corrupted in: start_kernel\")`, i.e. an unbootable system, or a panic during secondary-CPU bring-up via `start_secondary()` on hotplug/resume. This is total, unrecoverable loss of availability for the affected machine."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T09:14:23.246Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/25e73018b4093e0cfbcec5dc4a4bb86d0b69ed56"
        },
        {
          "url": "https://git.kernel.org/stable/c/514ca14ed5444b911de59ed3381dfd195d99fe4b"
        }
      ],
      "title": "start_kernel: Add __no_stack_protector function attribute",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2023-53491",
    "datePublished": "2025-10-01T11:45:43.101Z",
    "dateReserved": "2025-10-01T11:39:39.403Z",
    "dateUpdated": "2026-08-05T09:14:23.246Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}