Overview
About vulnerability
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. ]
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+2 more)
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. ]