CVE Catalog

CVE-2026-89742

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel, dma_req_free() in RapidIO mport_cdev drops the mapping reference via kref_put() and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, the object is freed and a use-after-free occurs.

Risk Assessment

A local user can trigger a use-after-free through the RapidIO mport character device interface, potentially leading to arbitrary code execution or system crash.

Recommendation

Update the Linux kernel to a version containing the fix that caches map and md before kref_put() and clears req->map while holding buf_mutex.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: rapidio: mport_cdev: fix use-after-free in dma_req_free() dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface.

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