CVE-2025-40225CVE-2025-40225

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Fix kernel panic on partial unmap of a GPU VA region This commit address a kernel panic issue that can happen if Userspace tries to partially unmap a GPU virtual region (aka drm_gpuva). The VM_BIND interface allows partial unmapping of a BO. Panthor driver pre-allocates memory for the new drm_gpuva structures that would be needed for the map/unmap operation, done using drm_gpuvm layer. It expected that only one new drm_gpuva would be needed on umap but a partial unmap can require 2 new drm_gpuva and that's why it ended up doing a NULL pointer dereference causing a kernel panic. Following dump was seen when partial unmap was exercised. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000078 Mem abort info: ESR = 0x0000000096000046 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort i