sched: Fix out-of-bound access in uclamp

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2021-46993
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2024-02-28 09:15:37 UTC
Updated2026-08-04 10:16:40 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 7.1 HIGH from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Problem Types: CWE-125

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.1HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 69842cba9ace84849bb9b8edcdf2cefccd97901c 687f523c134b7f0bd040ee1230f6d17990d54172 git Not specified
CNA Linux Linux affected 69842cba9ace84849bb9b8edcdf2cefccd97901c f7347c85490b92dd144fa1fba9e1eca501656ab3 git Not specified
CNA Linux Linux affected 69842cba9ace84849bb9b8edcdf2cefccd97901c 3da3f804b82a0a382d523a21acf4cf3bb35f936d git Not specified
CNA Linux Linux affected 69842cba9ace84849bb9b8edcdf2cefccd97901c 42ee47c7e3569d9a0e2cb5053c496d97d380472f git Not specified
CNA Linux Linux affected 69842cba9ace84849bb9b8edcdf2cefccd97901c 6d2f8909a5fabb73fe2a63918117943986c39b6c git Not specified
CNA Linux Linux affected 5.3 Not specified
CNA Linux Linux unaffected 5.3 semver Not specified
CNA Linux Linux unaffected 5.4.120 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.38 5.10.* semver Not specified
CNA Linux Linux unaffected 5.11.22 5.11.* semver Not specified
CNA Linux Linux unaffected 5.12.5 5.12.* semver Not specified
CNA Linux Linux unaffected 5.13 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/6d2f8909a5fabb73fe2a63918117943986c39b6c af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/42ee47c7e3569d9a0e2cb5053c496d97d380472f af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/f7347c85490b92dd144fa1fba9e1eca501656ab3 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/3da3f804b82a0a382d523a21acf4cf3bb35f936d af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/687f523c134b7f0bd040ee1230f6d17990d54172 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
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