Riskcovery

CVE-2021-46993

sched: Fix out-of-bound access in uclamp

State
Published
Severity
7.8 High
Published
Feb 28, 2024
Updated
Aug 5, 2026
Reserved
Feb 27, 2024

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 69842cba9ace84849bb9b8edcdf2cefccd97901c to before 687f523c134b7f0bd040ee1230f6d17990d54172Affected
  • 69842cba9ace84849bb9b8edcdf2cefccd97901c to before f7347c85490b92dd144fa1fba9e1eca501656ab3Affected
  • 69842cba9ace84849bb9b8edcdf2cefccd97901c to before 3da3f804b82a0a382d523a21acf4cf3bb35f936dAffected
  • 69842cba9ace84849bb9b8edcdf2cefccd97901c to before 42ee47c7e3569d9a0e2cb5053c496d97d380472fAffected
  • 69842cba9ace84849bb9b8edcdf2cefccd97901c to before 6d2f8909a5fabb73fe2a63918117943986c39b6cAffected
LinuxLinux
  • 5.3Affected
  • before 5.3Not affected
  • 5.4.120 through 5.4.*Not affected
  • 5.10.38 through 5.10.*Not affected
  • 5.11.22 through 5.11.*Not affected
  • 5.12.5 through 5.12.*Not affected
  • 5.13 and laterNot affected

References

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