In the Linux kernel, the following vulnerability has been resolved:
sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed
With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating that the cpuset will just use the effective CPUs of its parent. So cpuset_can_attach() can call task_can_attach() with an empty mask. This can lead to cpumask_any_and() returns nr_cpu_ids causing the call to dl_bw_of() to crash due to percpu value access of an out of bound CPU value. For example:
[80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0 : [80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0 : [80468.207946] Call Trace: [80468.208947] cpuset_can_attach+0xa0/0x140 [80468.209953] cgroup_migrate_execute+0x8c/0x490 [80468.210931] cgroup_update_dfl_csses+0x254/0x270 [80468.211898] cgroup_subtree_control_write+0x322/0x400 [80468.212854] kernfs_fop_write_iter+0x11c/0x1b0 [80468.213777] new_sync_write+0x11f/0x1b0 [80468.214689] vfs_write+0x1eb/0x280 [80468.215592] ksys_write+0x5f/0xe0 [80468.216463] do_syscall_64+0x5c/0x80 [80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix that by using effective_cpus instead. For cgroup v1, effective_cpus is the same as cpus_allowed. For v2, effective_cpus is the real cpumask to be used by tasks within the cpuset anyway.
Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to reflect the change. In addition, a check is added to task_can_attach() to guard against the possibility that cpumask_any_and() may return a value >= nr_cpu_ids.
CVSS Details
- CVSS 3.1 Base Score: 7.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-debuginfoUpgrade kernel-headersUpgrade bpftoolUpgrade kernel-tools-debuginfoUpgrade python-perfUpgrade bpftool-debuginfoUpgrade kernel-develUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-5.10.144-127.601Upgrade kernel-livepatch-5.15.69-37.134Upgrade perf-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-develUpgrade kernel-livepatch-4.14.355-280.652Upgrade kernelUpgrade kernel-toolsUpgrade perfUpgrade python-perf-debuginfo | Jul 9, 2025 | Jun 18, 2025 |
| Debian | — | Upgrade linux | Jun 20, 2025 | Jun 20, 2025 |
| Dell Powerstore Dsa2025429 | — | Upgrade Dell PowerStoreOS to the latest version | Dec 3, 2025 | Dec 2, 2025 |
| Dell Powerstore Dsa2026039 | — | Upgrade Dell PowerStoreOS to the latest version | Jan 13, 2026 | Jan 6, 2026 |
| Huawei Euleros 2_0_sp10 | — | Upgrade python3-perfUpgrade kernel-toolsUpgrade kernel-tools-libsUpgrade kernel-abi-stablelistsUpgrade kernel | Sep 15, 2025 | Sep 9, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade kernel-tools-libsUpgrade bpftoolUpgrade kernelUpgrade python3-perfUpgrade kernel-abi-stablelistsUpgrade kernel-tools | Nov 21, 2025 | Sep 9, 2025 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Jun 18, 2025 |
| Ubuntu | — | Upgrade linux-azure-5.15Upgrade linux-azureUpgrade linux-oracleUpgrade linux-hwe-5.15Upgrade linux-ibmUpgrade linux-riscv-5.15Upgrade linux-nvidiaUpgrade linux-gcp-5.15Upgrade linux-intel-iotg-5.15Upgrade linux-gkeopUpgrade linux-kvmUpgrade linux-lowlatencyUpgrade linux-oracle-5.15Upgrade linux-intel-iotgUpgrade linux-realtimeUpgrade linux-lowlatency-hwe-5.15Upgrade linuxUpgrade linux-awsUpgrade linux-raspiUpgrade linux-gkeUpgrade linux-gcpUpgrade linux-aws-5.15 | Jun 26, 2025 | Jun 18, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Jun 18, 2025 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub