CVE-2026-74703: vhost-scsi: Validate T10 PI scatterlist counts

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-22 · updated 2026-10-14

Description

In the Linux kernel, the following vulnerability has been resolved: vhost-scsi: Validate T10 PI scatterlist counts When T10 PI is negotiated, vhost-scsi splits protection bytes from the data iterator before mapping the request scatterlists. A malformed request can claim protection bytes that cover or exceed the full payload length. The former leaves no data bytes to map, while the latter underflows exp_data_len before advancing the iterator. Both cases can let a zero data SGL count reach sg_alloc_table_chained(), which triggers BUG_ON(!nents). Reject protection lengths that cover or exceed the payload before subtracting prot_bytes and advancing the iterator. Also propagate negative errors from the protection SGL calculation before calling the allocator, matching the data SGL path.

Affected products

Linux kernel: 6.15 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

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