Executive brief
A vulnerability in the AMD display driver for the Linux kernel can cause the entire system to crash. This occurs when the system attempts to allocate memory for specific display features while certain processor protections are active, leading to a kernel panic. This issue primarily affects stability and availability for users with AMD graphics hardware.
Technical details
A kernel panic (BUG_ON) occurs in the AMD display driver (drm/amd/display) specifically within the DCN32 resource management. The root cause is a call to kvzalloc() within a region where FPU registers are locked (DC_FP_START), which disables local softirqs on x86 non-RT systems. When kvzalloc() triggers the vmalloc path for allocations around 335 KiB, it invokes BUG_ON(in_interrupt()) because it is running in a context where preemption and softirqs are disabled. An attacker or a specific display configuration change could trigger this condition to cause a local Denial of Service. The fix involves wrapping the phantom-plane allocation in the DC_RUN_WITH_PREEMPTION_ENABLED macro to safely allow preemption during the allocation.
Affected products
- Linux Linux Kernel 6.0 to 7.0.10
Timeline
- 2026-05-05: other: Initial patch authored
- 2026-06-26: disclosed: CVE published