CVE Catalog

CVE-2026-64588

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel's FUSE-uring subsystem, there are data races on the ring->ready field. On weakly-ordered architectures, the store to fiq->ops can be reordered before the store to ring->ready, potentially leading to use of a stale fiq->ops pointer. Additionally, the fast-path read of ring->ready is unmarked, which KCSAN may flag.

Risk Assessment

The risk includes incorrect FUSE-uring behavior, potential crashes, or unpredictable system behavior in multi-processor environments.

Recommendation

It is recommended to update the Linux kernel to a version with the fix that applies appropriate memory barriers (smp_store_release, smp_load_acquire) and READ_ONCE for relevant reads.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix data races on ring->ready On weakly-ordered architectures, the store to fiq->ops can be reordered past the store to ring->ready, allowing a CPU that sees ring->ready == true via fuse_uring_ready() to dispatch requests through a stale fiq->ops pointer. Upgrade the store to smp_store_release() and the load in fuse_uring_ready() to smp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...) is visible to any CPU that observes ring->ready == true. Additionally, fuse_uring_do_register() publishes ring->ready with WRITE_ONCE() but the fast-path check reads it with a plain load. This is a marked-vs-unmarked access that KCSAN will flag. Wrap it in READ_ONCE() to mark it without adding unnecessary ordering. Also wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to prevent the compiler from reloading it between the NULL check and the dereference.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS