drm/panthor: reject firmware sections with oversized data

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: reject firmware sections with oversized data In panthor_fw_load_section_entry(), the data size to copy is calculated without validating it against the allocated section_size: section->data.size = hdr.data.end - hdr.data.start; If a crafted firmware sets data.size larger than the allocated memory, this could cause a heap buffer overflow in panthor_fw_init_section_mem() memcpy(section->mem->kmap, section->data.buf, section->data.size); Additionally, if the section->data.size exceeds the BO size, could this memset underflow the size calculation, leading to a massive out-of-bounds zeroing of kernel memory? memset(section->mem->kmap + section->data.size, 0, panthor_kernel_bo_size(section->mem) - section->data.size); Reject section entries whose initial data is larger than the section size.