Linux Kernel up to 7.3-rc3 IB/hfi1 hfi1_file_mmap vm_pgoff buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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8.7$5k-$25k0.00

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. Affected by this vulnerability is the function hfi1_file_mmap of the component IB/hfi1. Performing a manipulation of the argument vm_pgoff results in buffer overflow. This vulnerability is reported as CVE-2026-98216. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. This affects the function hfi1_file_mmap of the component IB/hfi1. The manipulation of the argument vm_pgoff with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: IB/hfi1: Fix the PIO_CRED credit-return mmap hfi1_file_mmap()'s PIO_CRED 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, cr_page_offset is a byte offset but .va is a struct credit_return *, so adding it is pointer arithmetic and scales the offset by sizeof(struct credit_return) == 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 vm_area, so dma_mmap_coherent() -> iommu_dma_mmap() finds no pages, vmalloc_to_pfn() returns page_to_pfn(NULL), and remap_pfn_range() installs a frame above MAXPHYADDR. The first user read then takes: psm2_ep_open_pr: 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, dma_mmap_coherent() describes a whole coherent buffer and selects the page within it with vma->vm_pgoff. Offsetting cpu_addr has no effect: for a vmap'd allocation iommu_dma_mmap() uses cpu_addr only to locate the vm_area and then maps pages[vm_pgoff], which hfi1_file_mmap() 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 vm_pgoff. 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 dma_direct_mmap() adds the same vm_pgoff 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 psm2_ep_open() Oopses the kernel; with only the arithmetic corrected psm2_ep_open() succeeds but any transfer that uses send PIO hangs, PSM2_SDMA=2 (send PIO disabled) completing normally while PSM2_SDMA=0 (send PIO only) hangs every time. With this change send PIO, send DMA and the default mixed mode all work.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-98216 since 09/25/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Additional levels of successful authentication are required for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/06/2026).

Upgrading to version 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 535530bb2ea5254e1e9f55280143d262dd065204/dcebe0b0bb080a25fe08011fd6b6e741f7912f01/180752deb7270ad37394ab6ef7cf4978fad040b3/bafeac9ce5d1ce5256bcf7e5702e831e9aaf419b/62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.158/6.12.112/6.18.54/7.2.8/7.3-rc4
Patch: 535530bb2ea5254e1e9f55280143d262dd065204/dcebe0b0bb080a25fe08011fd6b6e741f7912f01/180752deb7270ad37394ab6ef7cf4978fad040b3/bafeac9ce5d1ce5256bcf7e5702e831e9aaf419b/62f0f34fbd2b2d5653d33d3b9d42fdcabb1c0101

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98216 (🔒)
GCVE (CVE): GCVE-0-2026-98216
GCVE (VulDB): GCVE-100-414117

Entryinfo

Created: 10/06/2026 12:55
Changes: 10/06/2026 12:55 (60)
Complete: 🔍
Cache ID: 216::103

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