CVE-2026-80817CVE-2026-80817

In the Linux kernel, the following vulnerability has been resolved: iommu/iommufd: Fix NULL pointer deref in iommufd_ioas_change_process when racing with iopt_map_file_pages iommufd_ioas_change_process() iterates every IOAS area while only holding every IOAS iova_rwsem, so it assumes every area has a non-NULL pages pointer. That assumption can be false when it runs concurrently with iopt_map_file_pages(). iopt_map_pages() executes in two phases. It first creates the area and inserts it into the interval tree under iova_rwsem, with area->pages still NULL. It then drops iova_rwsem and later fills area->pages under domains_rwsem. This leaves a window between area creation and area->pages fill where a concurrent iommufd_ioas_change_process() can observe the area and dereference a NULL area->pages pointer, leading to a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 00000000000000c0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present