CVE-2022-49090: arch/arm64: Fix topology initialization for core scheduling
Vulnerability summary
CVE-2022-49090 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.9% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 5 · Related 4Timeline
- 26-02-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.25% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu89 products
- linux< 5.15.0-37.39
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1011.14
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 9edeaea1bc452372718837ed2ba775811baf1ba1, < 87f5d66daa5f457449bb95d6b8d18bb7596aa627 | ≥ 9edeaea1bc452372718837ed2ba775811baf1ba1, < 790c1567582bda8f1153015436e3330a7c6eb278 | ≥ 9edeaea1bc452372718837ed2ba775811baf1ba1, < c78a1b2d0bff678570c8dc9f14035606f5e5257d | ≥ 9edeaea1bc452372718837ed2ba775811baf1ba1, < 5524cbb1bfcdff0cad0aaa9f94e6092002a07259 | 5.14
- linux_kernel≥ 5.14, < 5.15.34 | ≥ 5.16, < 5.16.20 | ≥ 5.17, < 5.17.3 | 5.18:rc1
Debian1 product
- linux< 5.17.3-1
3 vendors · 92 products