Medium · published September 5, 2025
In the Linux kernel, the following vulnerability has been resolved:
x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper
Since
923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot")
resctrl_cpu_detect() has been moved from common CPU initialization code to
the vendor-specific BSP init helper, while Hygon didn't put that call in their
code.
This triggers a division by zero fault during early booting stage on our
machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries
to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale.
Add the missing resctrl_cpu_detect() in the Hygon BSP init helper.
[ bp: Massage commit message. ]
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.8, < 5.10.242 | 5.10.242 |
| linux/linux_kernel | ≥ 5.11, < 5.15.190 | 5.15.190 |
| linux/linux_kernel | ≥ 5.16, < 6.1.149 | 6.1.149 |
| linux/linux_kernel | ≥ 6.2, < 6.6.103 | 6.6.103 |
| linux/linux_kernel | ≥ 6.7, < 6.12.44 | 6.12.44 |
| linux/linux_kernel | ≥ 6.13, < 6.16.4 | 6.16.4 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| debian/debian_linux | all versions | — |