CVE-2021-46993

2024-02-2809:15:37

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

vulnerability

uclamp

performance

cve-2021-46993

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

JSON

In the Linux kernel, the following vulnerability has been resolved:

sched: Fix out-of-bound access in uclamp

Util-clamp places tasks in different buckets based on their clamp values
for performance reasons. However, the size of buckets is currently
computed using a rounding division, which can lead to an off-by-one
error in some configurations.

For instance, with 20 buckets, the bucket size will be 1024/20=51. A
task with a clamp of 1024 will be mapped to bucket id 1024/51=20. Sadly,
correct indexes are in range [0,19], hence leading to an out of bound
memory access.

Clamp the bucket id to fix the issue.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.3–5.4.120

linuxlinux_kernelRange5.5.0–5.10.38

linuxlinux_kernelRange5.11.0–5.11.22

linuxlinux_kernelRange5.12.0–5.12.5

linuxlinux_kernelRange5.13.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/sched/core.c"
    ],
    "versions": [
      {
        "version": "69842cba9ace",
        "lessThan": "687f523c134b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "69842cba9ace",
        "lessThan": "f7347c85490b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "69842cba9ace",
        "lessThan": "3da3f804b82a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "69842cba9ace",
        "lessThan": "42ee47c7e356",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "69842cba9ace",
        "lessThan": "6d2f8909a5fa",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/sched/core.c"
    ],
    "versions": [
      {
        "version": "5.3",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.3",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.120",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.38",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.11.22",
        "lessThanOrEqual": "5.11.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.5",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]