UBUNTU-CVE-2026-98216: High severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: IB/hfi1: Fix the PIOCRED credit-return mmap hfi1filemmap()'s PIOCRED case must hand user space the single credit-return page that holds this context's entry. That page is the second or third page of the per-node credit-return allocation once the hardware send context index reaches 64 or 128, so the failure below is intermittent: when the entry lands on the first page the offset is zero and everything works. Two things are wrong. First, crpageoffset is a byte offset but .va is a struct creditreturn , so adding it is pointer arithmetic and scales the offset by sizeof(struct creditreturn) == 64. memvirt then lands 256 KiB or 512 KiB past a 10240-byte allocation. With an IOMMU translating, that address is inside the vmalloc range but in no vmarea, so dmammapcoherent() -> iommudmammap() finds no pages, vmalloctopfn() returns pagetopfn(NULL), and remappfnrange() installs a frame above MAXPHYADDR. The first user read then takes: psm2epopenpr: Corrupted page table at address 7a14d007e000 PGD 800000013886a067 P4D 800000013886a067 PUD 13886b067 PMD 13886c067 PTE 800049168e911235 Oops: Bad pagetable: 000d [#1] SMP PTI Second, and still wrong once the arithmetic is corrected, dmammapcoherent() describes a whole coherent buffer and selects the page within it with vma->vmpgoff. Offsetting cpuaddr has no effect: for a vmap'd allocation iommudmammap() uses cpuaddr only to locate the vmarea and then maps pages[vmpgoff], which hfi1filemmap() has just set to 0. User space therefore always receives the first credit-return page, every credit read is for the wrong context, and send PIO stalls forever. Use the DMA API as intended: pass the base of the allocation with its full length and select the page with vmpgoff. A separate length is needed because memlen must keep describing the VMA for the existing size check. The dma-direct path stays correct as well, since dmadirectmmap() adds the same vmpgoff to the base pfn. Tested on a Dell T7610 (Xeon E5-2650 v2, Intel IOMMU in DMA-FQ mode) against a Threadripper PRO 3995WX peer, both Omni-Path 100. Before this change psm2epopen() Oopses the kernel; with only the arithmetic corrected psm2epopen() succeeds but any transfer that uses send PIO hangs, PSM2SDMA=2 (send PIO disabled) completing normally while PSM2SDMA=0 (send PIO only) hangs every time. With this change send PIO, send DMA and the default mixed mode all work.