CVE-2021-46993
sched: Fix out-of-bound access in uclamp
- Published
- Updated
- Reserved
- Assigned by
- Linux
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.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 84% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 69842cba9ace84849bb9b8edcdf2cefccd97901c – < 687f523c134b7f0bd040ee1230f6d17990d54172
- affected 69842cba9ace84849bb9b8edcdf2cefccd97901c – < f7347c85490b92dd144fa1fba9e1eca501656ab3
- affected 69842cba9ace84849bb9b8edcdf2cefccd97901c – < 3da3f804b82a0a382d523a21acf4cf3bb35f936d
- affected 69842cba9ace84849bb9b8edcdf2cefccd97901c – < 42ee47c7e3569d9a0e2cb5053c496d97d380472f
- affected 69842cba9ace84849bb9b8edcdf2cefccd97901c – < 6d2f8909a5fabb73fe2a63918117943986c39b6c
- affected 5.3
- unaffected < 5.3
- unaffected 5.4.120 – ≤ 5.4.*
- unaffected 5.10.38 – ≤ 5.10.*
- unaffected 5.11.22 – ≤ 5.11.*
- unaffected 5.12.5 – ≤ 5.12.*
- unaffected 5.13 – ≤ *
References (5)
- https://git.kernel.org/stable/c/687f523c134b7f0bd040ee1230f6d17990d54172 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/f7347c85490b92dd144fa1fba9e1eca501656ab3 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/3da3f804b82a0a382d523a21acf4cf3bb35f936d (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/42ee47c7e3569d9a0e2cb5053c496d97d380472f (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/6d2f8909a5fabb73fe2a63918117943986c39b6c (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-46993)Record last updated .