SEPTEMBER 17, 2026
Live Feed
Back to database
Case File

CVE-2026-64232

CRITICAL · CVSS 9.8 EPSS 0.46%

Source: NVD + CISA KEV + EPSS · Published 2026-07-24 · Last synced 2026-08-23

CyberRota Analysis

AI-Generated

A critical vulnerability in the Linux kernel affects the integrity segment counting in block request handling, specifically within the `blk_insert_cloned_request()` function. This flaw can lead to a situation where the cached integrity segment count is lower than the actual count required by the underlying queue, resulting in potential system crashes or data integrity issues during request dispatch. Organizations utilizing Linux systems, particularly those employing complex storage configurations like dm-multipath with NVMe-RDMA, should prioritize patching this vulnerability to mitigate risks associated with data corruption and system stability.

CVE
CVE-2026-64232
Severity
CRITICAL
CVSS
9.8
EPSS
0.46%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: block: recompute nr_integrity_segments in blk_insert_cloned_request blk_insert_cloned_request() already recomputes nr_phys_segments against the bottom queue, because "the queue settings related to segment counting may differ from the original queue." The exact same reasoning applies to integrity segments: a stacked driver's underlying queue can have tighter virt_boundary_mask, seg_boundary_mask, or max_segment_size than the top queue, in which case blk_rq_count_integrity_sg() against the bottom queue produces a different count than the cached rq->nr_integrity_segments inherited from the source request by blk_rq_prep_clone(). When the cached count is lower than the bottom queue's actual count, blk_rq_map_integrity_sg() trips BUG_ON(segments > rq->nr_integrity_segments); on dispatch. The same families of stacked setups that motivated the existing nr_phys_segments recompute -- dm-multipath fanning out to nvme-rdma in particular -- can produce this. Mirror the nr_phys_segments handling: when the request carries integrity, recompute nr_integrity_segments against the bottom queue and reject the request if it exceeds the bottom queue's max_integrity_segments. blk_rq_count_integrity_sg() and queue_max_integrity_segments() are both already available via <linux/blk-integrity.h>, which blk-mq.c includes. This closes a latent gap in the stacking contract and brings the integrity-segment accounting in line with the existing phys-segment accounting.

Related CVEs

Other vulnerabilities affecting the same vendor(s)