CVE-2025-21919 — sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

Affected: Linux, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

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

sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

child_cfs_rq_on_list attempts to convert a 'prev' pointer to a cfs_rq. This 'prev' pointer can originate from struct rq's leaf_cfs_rq_list, making the conversion invalid and potentially leading to memory corruption. Depending on the relative positions of leaf_cfs_rq_list and the task group (tg) pointer within the struct, this can cause a memory fault or access garbage data.

The issue arises in list_add_leaf_cfs_rq, where both cfs_rq->leaf_cfs_rq_list and rq->leaf_cfs_rq_list are added to the same leaf list. Also, rq->tmp_alone_branch can be set to rq->leaf_cfs_rq_list.

This adds a check `if (prev == &rq->leaf_cfs_rq_list)` after the main conditional in child_cfs_rq_on_list. This ensures that the container_of operation will convert a correct cfs_rq struct.

This check is sufficient because only cfs_rqs on the same CPU are added to the list, so verifying the 'prev' pointer against the current rq's list head is enough.

Fixes a potential memory corruption issue that due to current struct layout might not be manifesting as a crash but could lead to unpredictable behavior when the layout changes.

USN-7510-1 — linux, linux-gkeop, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15…

Affected: Ubuntu:20.04:LTS: linux-ibm-5.15, Ubuntu:20.04:LTS: linux-lowlatency-hwe-5.15, Ubuntu:20.04:LTS: linux-oracle-5.15, Ubuntu:22.04:LTS: linux, Ubuntu:22.04:LTS: linux-gkeop, Ubuntu:22.04:LTS: linux-ibm, Ubuntu:22.04:LTS: linux-intel-iotg, Ubuntu:22.04:LTS: linux-kvm, Ubuntu:22.04:LTS: linux-lowlatency, Ubuntu:22.04:LTS: linux-nvidia and 1 more

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM64 architecture; - PowerPC architecture; - x86 architecture; - Block layer subsystem; - Network block device driver; - Bus devices; - Character device driver; - TPM device driver; - Clock framework and drivers; - GPIO subsystem; - GPU drivers; - HID subsystem; - I2C subsystem; - InfiniBand drivers; - Media drivers; - NVIDIA Tegra memory controller driver; - Network drivers; - PCI subsystem; - PPS (Pulse Per Second) driver; - PTP clock framework; - RapidIO drivers; - Real Time Clock drivers; - SLIMbus drivers; - QCOM SoC drivers; - Trusted Execution Environment drivers; - TTY drivers; - USB DSL drivers; - USB Device Class drivers; - USB core drivers; - USB Gadget drivers; - USB Host Controller drivers; - Renesas USBHS Controller drivers; - ACRN Hypervisor Service Module driver; - File systems infrastructure; - BTRFS file system; - F2FS file system; - Network file system (NFS) server daemon; - NILFS2 file system; - Overlay file system; - SMB network file system; - UBI file system; - KVM subsystem; - L3 Master device support module; - Process Accounting mechanism; - Padata parallel execution mechanism; - printk logging mechanism; - Scheduler infrastructure; - Timer subsystem; - Tracing infrastructure…

Most recent entries from all

CVE-2025-21919 — sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

USN-7510-1 — linux, linux-gkeop, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15…