The Linux kernel ethosu driver mishandles the NPU_OP_RESIZE command submitted via DRM_IOCTL_ETHOSU_GEM_CREATE. This command is specific to U85 hardware and is not implemented by the driver. Previously, the driver triggered a WARN_ON(1) unconditionally when this command was received, causing excessive kernel log spam. If the kernel is configured with panic_on_warn, this leads to a kernel panic, enabling a trivial denial-of-service attack by any unprivileged user with DRM device access. The fix replaces the WARN_ON(1) with an explicit -EINVAL return, rejecting the command before hardware interaction.

Unprivileged users with access to the DRM device can cause unbounded kernel log spam and potentially trigger a kernel panic if panic_on_warn is enabled, resulting in a denial-of-service condition. There is no impact on confidentiality or integrity.

A fix has been implemented that replaces the WARN_ON(1) with an explicit -EINVAL return to reject the unsupported NPU_OP_RESIZE command. Users should apply the official kernel update containing this fix when available. Until then, restricting unprivileged access to the DRM device can reduce risk. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.