CVE-2021-46993

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.

• linux linux kernel (>= 5.3 < 5.4.120) • linux linux kernel (>= 5.5 < 5.10.38) • linux linux kernel (>= 5.11 < 5.11.22) • linux linux kernel (>= 5.12 < 5.12.5)