CVE-2021-46993
Medium
Elevated severity or exploit probability.
CVSS base
7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.2%
15.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-125
Published 2024-02-28 · modified 2026-08-04
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2024-02-28 — Published (NVD)
- 2026-08-04 — Last modified (NVD)
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.
Affected
References
- https://git.kernel.org/stable/c/3da3f804b82a0a382d523a21acf4cf3bb35f936d
- https://git.kernel.org/stable/c/42ee47c7e3569d9a0e2cb5053c496d97d380472f
- https://git.kernel.org/stable/c/687f523c134b7f0bd040ee1230f6d17990d54172
- https://git.kernel.org/stable/c/6d2f8909a5fabb73fe2a63918117943986c39b6c
- https://git.kernel.org/stable/c/f7347c85490b92dd144fa1fba9e1eca501656ab3
- https://git.kernel.org/stable/c/3da3f804b82a0a382d523a21acf4cf3bb35f936d
- https://git.kernel.org/stable/c/42ee47c7e3569d9a0e2cb5053c496d97d380472f
- https://git.kernel.org/stable/c/687f523c134b7f0bd040ee1230f6d17990d54172
- https://git.kernel.org/stable/c/6d2f8909a5fabb73fe2a63918117943986c39b6c
- https://git.kernel.org/stable/c/f7347c85490b92dd144fa1fba9e1eca501656ab3