CVE-2021-46993

published 2024-02-28

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…

Priority P4 29 high 7.1 CVSS 3.1

AV L AC L PR L UI N S U C H I N A H

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

15 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 5.10.38-1 (bookworm)	linux 5.10.38-1 (bookworm)
linux	linux	—	—
linux	linux	>= 69842cba9ace84849bb9b8edcdf2cefccd97901c < 687f523c134b7f0bd040ee1230f6d17990d54172	687f523c134b7f0bd040ee1230f6d17990d54172
linux	linux	>= 69842cba9ace84849bb9b8edcdf2cefccd97901c < f7347c85490b92dd144fa1fba9e1eca501656ab3	f7347c85490b92dd144fa1fba9e1eca501656ab3
linux	linux	>= 69842cba9ace84849bb9b8edcdf2cefccd97901c < 3da3f804b82a0a382d523a21acf4cf3bb35f936d	3da3f804b82a0a382d523a21acf4cf3bb35f936d
linux	linux	>= 69842cba9ace84849bb9b8edcdf2cefccd97901c < 42ee47c7e3569d9a0e2cb5053c496d97d380472f	42ee47c7e3569d9a0e2cb5053c496d97d380472f
linux	linux	>= 69842cba9ace84849bb9b8edcdf2cefccd97901c < 6d2f8909a5fabb73fe2a63918117943986c39b6c	6d2f8909a5fabb73fe2a63918117943986c39b6c
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 5.11 < 5.11.22	5.11.22
linux	linux_kernel	>= 5.12 < 5.12.5	5.12.5
linux	linux_kernel	>= 5.3 < 5.4.120	5.4.120
linux	linux_kernel	>= 5.5 < 5.10.38	5.10.38

CVSS provenance

nvd v3.1 7.1 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

osv 7.1 HIGH

vendor_debian 7.1 HIGH

vendor_redhat 7.1 HIGH

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CWE-125