https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-16T00:42:57.971108+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2025-21632 CVE-2025-21632 — x86/fpu: Ensure shadow stack is active before "getting" registers 2026-10-16T00:42:58.013121+00:00

Affected: Linux

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

x86/fpu: Ensure shadow stack is active before "getting" registers

The x86 shadow stack support has its own set of registers. Those registers are XSAVE-managed, but they are "supervisor state components" which means that userspace can not touch them with XSAVE/XRSTOR. It also means that they are not accessible from the existing ptrace ABI for XSAVE state. Thus, there is a new ptrace get/set interface for it.

The regset code that ptrace uses provides an ->active() handler in addition to the get/set ones. For shadow stack this ->active() handler verifies that shadow stack is enabled via the ARCH_SHSTK_SHSTK bit in the thread struct. The ->active() handler is checked from some call sites of the regset get/set handlers, but not the ptrace ones. This was not understood when shadow stack support was put in place.

As a result, both the set/get handlers can be called with XFEATURE_CET_USER in its init state, which would cause get_xsave_addr() to return NULL and trigger a WARN_ON(). The ssp_set() handler luckily has an ssp_active() check to avoid surprising the kernel with shadow stack behavior when the kernel is not ready for it (ARCH_SHSTK_SHSTK==0). That check just happened to avoid the warning.

But the ->get() side wasn't so lucky. It can be called with shadow stacks disabled, triggering the warning in practice, as reported by Christina Schimpe:

WARNING: CPU: 5 PID: 1773 at arch/x86/kernel/fpu/regset.c:198…

 https://cve.radiocsirt.org/vuln/usn-7379-1 USN-7379-1 — linux, linux-aws, linux-azure, linux-gcp, linux-hwe-6.11, linux-oracle, linux-realtime vulnerabilities 2026-10-16T00:42:58.013255+00:00

Affected: Ubuntu:24.04:LTS: linux-hwe-6.11

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; - MIPS architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - x86 architecture; - Block layer subsystem; - Compute Acceleration Framework; - ACPI drivers; - Drivers core; - Ublk userspace block driver; - Virtio block driver; - Bluetooth drivers; - Buffer Sharing and Synchronization framework; - DMA engine subsystem; - EFI core; - GPIO subsystem; - GPU drivers; - HID subsystem; - Microsoft Hyper-V drivers; - Hardware monitoring drivers; - I3C subsystem; - IIO ADC drivers; - IIO subsystem; - InfiniBand drivers; - IOMMU subsystem; - LED subsystem; - Multiple devices driver; - Media drivers; - Microchip PCI driver; - MTD block device drivers; - Network drivers; - Mellanox network drivers; - STMicroelectronics network drivers; - NVME drivers; - PCI subsystem; - PHY drivers; - Pin controllers subsystem; - x86 platform drivers; - i.MX PM domains; - Power supply drivers; - Voltage and Current Regulator drivers; - SCSI subsystem; - i.MX SoC drivers; - SPI subsystem; - UFS subsystem; - USB Gadget drivers; - TDX Guest driver; - AFS file system; - BTRFS file system; - Ceph distributed file system; - File systems infrastructure; - F2FS file system; - JFFS…