{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98216", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.326Z", "datePublished": "2026-10-06T08:44:52.288Z", "dateUpdated": "2026-10-19T09:15:47.022Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:15:47.022Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bad mapping is created by hfi1_file_mmap() PIO_CRED case, reached by a local process via open() of the /dev/hfi1_N user cdev, the ASSIGN_CTXT ioctl and mmap() of the PIO_CRED token; no remote peer supplies any data to this path.\nAC:L - With IOMMU DMA translation (common on x86 servers), the pointer-scaled cr_page_offset deterministically sends memvirt 256/512 KiB past the credit-return buffer for send context index >=64, and the attacker can raise the index by opening more contexts; the commit's reproducer oopses every time.\nPR:L - hfi1_user_devnode() creates the user device node with mode 0666 and hfi1_file_open() has no capability check, so any unprivileged local user on an Omni-Path node (e.g. a shared HPC node) can assign a context and issue the mmap.\nUI:N - The attacker triggers the faulty mapping and the faulting read entirely from their own process; no other user or administrator has to do anything.\nS:U - Both impacts stay within the host kernel's own authority: a kernel page or bogus PFN is mapped into a local process and the kernel oopses; no VM, IOMMU or sandbox boundary is crossed.\nC:H - If the out-of-range vmalloc address lands in a non-DMA-coherent vm_area, iommu_dma_mmap() falls back to vmalloc_to_pfn() and remap_pfn_range() exposes that kernel page to userspace read-only with no reference held, so the user can read unrelated kernel memory, even after it is freed and reused.\nI:N - The PIO_CRED VMA is read-only: VM_WRITE is rejected with -EPERM and VM_MAYWRITE is cleared, so the mis-mapped page cannot be written from userspace, and the bug gives no kernel write primitive.\nA:H - When the address falls in a vmalloc hole, page_to_pfn(NULL) installs a PTE for a frame above MAXPHYADDR and the first user read causes an 'Oops: Bad pagetable' kernel crash; even with the arithmetic fixed, mapping the wrong page leaves send PIO hung forever." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/hw/hfi1/file_ops.c" ], "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" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/hw/hfi1/file_ops.c" ], "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" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.18.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/535530bb2ea5254e1e9f55280143d262dd065204" }, { "url": "https://git.kernel.org/stable/c/dcebe0b0bb080a25fe08011fd6b6e741f7912f01" }, { "url": "https://git.kernel.org/stable/c/180752deb7270ad37394ab6ef7cf4978fad040b3" }, { "url": "https://git.kernel.org/stable/c/bafeac9ce5d1ce5256bcf7e5702e831e9aaf419b" }, { "url": "https://git.kernel.org/stable/c/62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101" } ], "title": "IB/hfi1: Fix the PIO_CRED credit-return mmap", "x_generator": { "engine": "bippy-1.2.0" } } } }