CVE-2024-58091 addresses a vulnerability in the Linux kernel's drm/fbdev-dma subsystem related to deferred I/O handling. The issue arises because DMA areas may not be backed by struct page, which is necessary for deferred I/O operations. The fix introduces a shadow buffer to serve as framebuffer memory for drivers requiring deferred I/O, preventing kernel NULL pointer dereferences and paging request errors. This change ensures deferred I/O cannot be used without the shadow buffer, improving kernel stability.