CVE-2026-23168

A deadlock vulnerability was found in the Linux kernel's flexible proportions (fprop) code used for I/O writeback accounting. When a hardirq interrupts the seqcount write section in fprop_new_period() during softirq context, a reader in the hardirq handler can spin indefinitely waiting for the odd sequence number to become even, causing a system hang.

This deadlock primarily affects FUSE filesystems that configure maximum writeback throughput fractions. Standard local filesystems rarely trigger this condition. The issue results in a denial of service (system hang) but cannot be exploited for code execution or data compromise.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.