Linux kernel amdgpu display core (DC/DM) (drm/amd/display): A NULL pointer dereference in the amdgpu display core

Impact

A NULL pointer dereference in the amdgpu display core (DC/DM). An unchecked pointer - typically an optional IP block, an absent connector, or a failed allocation - is dereferenced on an error or corner-case path, panicking the kernel. There is no data disclosure here, but on a shared GPU node the blast radius is the whole machine: the panic kills every tenant's job on that host, not just the one that triggered it, and long training runs lose everything since the last checkpoint. Upstream fix: drm/amd/display: Add missing NULL pointer check within dpcd_extend_address_range

Who can reach it

Local. Reachable by a local user with access to the DRM primary node, or an attacker who controls the attached display's EDID/DisplayPort topology. On headless Instinct nodes the display block is largely unused, which cuts real exposure sharply. Not reachable over the network and not reachable from a container that has no GPU device node mapped in.

What to do

Kernel-side fix: this lands in mainline Linux and flows into distro kernels (RHEL/Rocky, Ubuntu HWE, SLES) and into AMD's out-of-tree DKMS amdgpu package shipped with ROCm. Patch the kernel or the DKMS module, then **reload the amdgpu module or reboot the node** - you cannot fix a running driver in place. Reloading amdgpu requires no process holding /dev/kfd or a render node, so in practice this is a cordon + drain + reboot per node. Plan it as a rolling maintenance across the fleet; there is no VBIOS flash, no SBIOS/AGESA step and no firmware update involved. Nodes running the ROCm DKMS stack often lag mainline by a release or two, so confirm the fix is actually present in the AMD driver version you deploy rather than assuming a new distro kernel covers it.

References