{"schema":"threatline.record/2","record":{"id":"CVE-2026-98216","aliases":[],"summary":"IB/hfi1: Fix the PIO_CRED credit-return mmap","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nIB/hfi1: Fix the PIO_CRED credit-return mmap\n\nhfi1_file_mmap()'s PIO_CRED case must hand user space the single\ncredit-return page that holds this context's entry.  That page is the\nsecond or third page of the per-node credit-return allocation once the\nhardware send context index reaches 64 or 128, so the failure below is\nintermittent: when the entry lands on the first page the offset is zero\nand everything works.\n\nTwo things are wrong.\n\nFirst, cr_page_offset is a byte offset but .va is a struct\ncredit_return *, so adding it is pointer arithmetic and scales the offset\nby sizeof(struct credit_return) == 64.  memvirt then lands 256 KiB or\n512 KiB past a 10240-byte allocation.  With an IOMMU translating, that\naddress is inside the vmalloc range but in no vm_area, so\ndma_mmap_coherent() -> iommu_dma_mmap() finds no pages, vmalloc_to_pfn()\nreturns page_to_pfn(NULL), and remap_pfn_range() installs a frame above\nMAXPHYADDR.  The first user read then takes:\n\n  psm2_ep_open_pr: Corrupted page table at address 7a14d007e000\n  PGD 800000013886a067 P4D 800000013886a067 PUD 13886b067 PMD 13886c067\n                                            PTE 800049168e911235\n  Oops: Bad pagetable: 000d [#1] SMP PTI\n\nSecond, and still wrong once the arithmetic is corrected,\ndma_mmap_coherent() describes a whole coherent buffer and selects the\npage within it with vma->vm_pgoff.  Offsetting cpu_addr has no effect:\nfor a vmap'd allocation iommu_dma_mmap() uses cpu_addr only to locate the\nvm_area and then maps pages[vm_pgoff], which hfi1_file_mmap() has just\nset to 0.  User space therefore always receives the first credit-return\npage, every credit read is for the wrong context, and send PIO stalls\nforever.\n\nUse the DMA API as intended: pass the base of the allocation with its\nfull length and select the page with vm_pgoff.  A separate length is\nneeded because memlen must keep describing the VMA for the existing size\ncheck.  The dma-direct path stays correct as well, since dma_direct_mmap()\nadds the same vm_pgoff to the base pfn.\n\nTested on a Dell T7610 (Xeon E5-2650 v2, Intel IOMMU in DMA-FQ mode)\nagainst a Threadripper PRO 3995WX peer, both Omni-Path 100.  Before this\nchange psm2_ep_open() Oopses the kernel; with only the arithmetic\ncorrected psm2_ep_open() succeeds but any transfer that uses send PIO\nhangs, PSM2_SDMA=2 (send PIO disabled) completing normally while\nPSM2_SDMA=0 (send PIO only) hangs every time.  With this change send PIO,\nsend DMA and the default mixed mode all work.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","source_modified_at":"2026-10-19T09:15:47.022Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"1ec82317a1daac78c04b0c15af89018ccf9fa2b7","lessThan":"535530bb2ea5254e1e9f55280143d262dd065204","status":"affected","versionType":"git"},{"version":"1ec82317a1daac78c04b0c15af89018ccf9fa2b7","lessThan":"dcebe0b0bb080a25fe08011fd6b6e741f7912f01","status":"affected","versionType":"git"},{"version":"1ec82317a1daac78c04b0c15af89018ccf9fa2b7","lessThan":"180752deb7270ad37394ab6ef7cf4978fad040b3","status":"affected","versionType":"git"},{"version":"1ec82317a1daac78c04b0c15af89018ccf9fa2b7","lessThan":"bafeac9ce5d1ce5256bcf7e5702e831e9aaf419b","status":"affected","versionType":"git"},{"version":"1ec82317a1daac78c04b0c15af89018ccf9fa2b7","lessThan":"62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","source_modified_at":"2026-10-19T09:15:47.022Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.3","status":"affected"},{"version":"0","lessThan":"6.3","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.54","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","source_modified_at":"2026-10-19T09:15:47.022Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"535530bb2ea5254e1e9f55280143d262dd065204","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","source_modified_at":"2026-10-19T09:15:47.022Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"180752deb7270ad37394ab6ef7cf4978fad040b3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","source_modified_at":"2026-10-19T09:15:47.022Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101","basis":"first unaffected version stated in the CVE record"}],"cvss":7.1,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00131,"percentile":0.02431,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:44:52.288Z","modified_at":"2026-10-19T09:15:47.022Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98216","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:15:47.022Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98216","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/535530bb2ea5254e1e9f55280143d262dd065204"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/dcebe0b0bb080a25fe08011fd6b6e741f7912f01"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/180752deb7270ad37394ab6ef7cf4978fad040b3"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/bafeac9ce5d1ce5256bcf7e5702e831e9aaf419b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:15:47.022Z","content_hash":"4220dfef56feaa9040c24ba9e992ce6c4f92a79b53d097e7b73ee77b7a955b04"}}