Description
In the Linux kernel, the following vulnerability has been resolved:

arch/arm64: Fix topology initialization for core scheduling

Arm64 systems rely on store_cpu_topology() to call update_siblings_masks()
to transfer the toplogy to the various cpu masks. This needs to be done
before the call to notify_cpu_starting() which tells the scheduler about
each cpu found, otherwise the core scheduling data structures are setup
in a way that does not match the actual topology.

With smt_mask not setup correctly we bail on `cpumask_weight(smt_mask) == 1`
for !leaders in:

notify_cpu_starting()
cpuhp_invoke_callback_range()
sched_cpu_starting()
sched_core_cpu_starting()

which leads to rq->core not being correctly set for !leader-rq's.

Without this change stress-ng (which enables core scheduling in its prctl
tests in newer versions -- i.e. with PR_SCHED_CORE support) causes a warning
and then a crash (trimmed for legibility):

[ 1853.805168] ------------[ cut here ]------------
[ 1853.809784] task_rq(b)->core != rq->core
[ 1853.809792] WARNING: CPU: 117 PID: 0 at kernel/sched/fair.c:11102 cfs_prio_less+0x1b4/0x1c4
...
[ 1854.015210] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
...
[ 1854.231256] Call trace:
[ 1854.233689] pick_next_task+0x3dc/0x81c
[ 1854.237512] __schedule+0x10c/0x4cc
[ 1854.240988] schedule_idle+0x34/0x54
Published: 2025-02-26
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2022-55114 In the Linux kernel, the following vulnerability has been resolved: arch/arm64: Fix topology initialization for core scheduling Arm64 systems rely on store_cpu_topology() to call update_siblings_masks() to transfer the toplogy to the various cpu masks. This needs to be done before the call to notify_cpu_starting() which tells the scheduler about each cpu found, otherwise the core scheduling data structures are setup in a way that does not match the actual topology. With smt_mask not setup correctly we bail on `cpumask_weight(smt_mask) == 1` for !leaders in: notify_cpu_starting() cpuhp_invoke_callback_range() sched_cpu_starting() sched_core_cpu_starting() which leads to rq->core not being correctly set for !leader-rq's. Without this change stress-ng (which enables core scheduling in its prctl tests in newer versions -- i.e. with PR_SCHED_CORE support) causes a warning and then a crash (trimmed for legibility): [ 1853.805168] ------------[ cut here ]------------ [ 1853.809784] task_rq(b)->core != rq->core [ 1853.809792] WARNING: CPU: 117 PID: 0 at kernel/sched/fair.c:11102 cfs_prio_less+0x1b4/0x1c4 ... [ 1854.015210] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... [ 1854.231256] Call trace: [ 1854.233689] pick_next_task+0x3dc/0x81c [ 1854.237512] __schedule+0x10c/0x4cc [ 1854.240988] schedule_idle+0x34/0x54
History

Tue, 23 Sep 2025 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.18:rc1:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Fri, 16 May 2025 03:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Thu, 27 Feb 2025 13:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Wed, 26 Feb 2025 02:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: arch/arm64: Fix topology initialization for core scheduling Arm64 systems rely on store_cpu_topology() to call update_siblings_masks() to transfer the toplogy to the various cpu masks. This needs to be done before the call to notify_cpu_starting() which tells the scheduler about each cpu found, otherwise the core scheduling data structures are setup in a way that does not match the actual topology. With smt_mask not setup correctly we bail on `cpumask_weight(smt_mask) == 1` for !leaders in: notify_cpu_starting() cpuhp_invoke_callback_range() sched_cpu_starting() sched_core_cpu_starting() which leads to rq->core not being correctly set for !leader-rq's. Without this change stress-ng (which enables core scheduling in its prctl tests in newer versions -- i.e. with PR_SCHED_CORE support) causes a warning and then a crash (trimmed for legibility): [ 1853.805168] ------------[ cut here ]------------ [ 1853.809784] task_rq(b)->core != rq->core [ 1853.809792] WARNING: CPU: 117 PID: 0 at kernel/sched/fair.c:11102 cfs_prio_less+0x1b4/0x1c4 ... [ 1854.015210] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... [ 1854.231256] Call trace: [ 1854.233689] pick_next_task+0x3dc/0x81c [ 1854.237512] __schedule+0x10c/0x4cc [ 1854.240988] schedule_idle+0x34/0x54
Title arch/arm64: Fix topology initialization for core scheduling
References

Subscriptions

Linux Linux Kernel
Redhat Enterprise Linux
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T18:52:54.316Z

Reserved: 2025-02-26T01:49:39.249Z

Link: CVE-2022-49090

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-02-26T07:00:46.337

Modified: 2025-09-23T18:12:21.107

Link: CVE-2022-49090

cve-icon Redhat

Severity : Low

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2022-49090 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses