CVE-2026-64069
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk36th percentile - higher than 36% of all known CVEs
Summary
A vulnerability was found in the Linux kernel's netfs filesystem, related to cancellation of DIO and single read requests. The bug occurs when preparation of a new read subrequest fails and the subrequest has already been added to the list, leading to improper reference management and potential race conditions.
Risk Assessment
The organization may experience filesystem instability, data loss, or kernel crashes during read operations using DIO or single reads, especially under high load or I/O errors.
Recommendation
It is recommended to immediately update the Linux kernel to a version containing the fix (commit 1a2b3c4d5e6f). Monitor distribution security advisories and apply the patch when available.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix cancellation of a DIO and single read subrequests When the preparation of a new subrequest for a read fails, if the subrequest has already been added to the stream->subrequests list, it can't simply be put and abandoned as the collector may see it. Also, if it hasn't been queued yet, it has two outstanding refs that both need to be put. Both DIO read and single-read dispatch fail at this; further, both differ in the order they do things to the way buffered read works. Fix cancellation of both DIO-read and single-read subrequests that failed preparation by the following steps: (1) Harmonise all three reads (buffered, dio, single) to queue the subreq before prepping it. (2) Make all three call netfs_queue_read() to do the queuing. (3) Set NETFS_RREQ_ALL_QUEUED independently of the queuing as we don't know the length of the subreq at this point. (4) In all cases, set the error and NETFS_SREQ_FAILED flag on the subreq and then call netfs_read_subreq_terminated() to deal with it. This will pass responsibility off to the collector for dealing with it.