title: sched: Fix out-of-bound access in uclamp
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:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 69842cba9ace, lessThan: 687f523c134b, status: affected, versionType: git
version: 69842cba9ace, lessThan: f7347c85490b, status: affected, versionType: git
version: 69842cba9ace, lessThan: 3da3f804b82a, status: affected, versionType: git
version: 69842cba9ace, lessThan: 42ee47c7e356, status: affected, versionType: git
version: 69842cba9ace, lessThan: 6d2f8909a5fa, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.3, status: affected
version: 0, lessThan: 5.3, status: unaffected, versionType: custom
version: 5.4.120, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.38, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.11.22, lessThanOrEqual: 5.11.*, status: unaffected, versionType: custom
version: 5.12.5, lessThanOrEqual: 5.12.*, status: unaffected, versionType: custom
version: 5.13, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
