1.3 KiB
CVE-2023-52455
Description
In the Linux kernel, the following vulnerability has been resolved:iommu: Don't reserve 0-length IOVA regionWhen the bootloader/firmware doesn't setup the framebuffers, theiraddress and size are 0 in "iommu-addresses" property. If IOVA region isreserved with 0 length, then it ends up corrupting the IOVA rbtree withan entry which has pfn_hi < pfn_lo.If we intend to use display driver in kernel without framebuffer thenit's causing the display IOMMU mappings to fail as entire valid IOVAspace is reserved when address and length are passed as 0.An ideal solution would be firmware removing the "iommu-addresses"property and corresponding "memory-region" if display is not present.But the kernel should be able to handle this by checking for size ofIOVA region and skipping the IOVA reservation if size is 0. Also, adda warning if firmware is requesting 0-length IOVA region reservation.
POC
Reference
No PoCs from references.