CVE Catalog

CVE-2025-39715

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

4th percentile - higher than 4% of all known CVEs

Summary

In the Linux kernel on parisc, gateway LWS calls were revised to probe user read access at privilege level 3. Previously, user code could perform a LWS compare-and-swap on a read-protected address.

Risk Assessment

Read protection may be bypassed, allowing unauthorized data modification. Affects parisc systems.

Recommendation

Update the Linux kernel on parisc systems to a patched version.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: parisc: Revise gateway LWS calls to probe user read access We use load and stbys,e instructions to trigger memory reference interruptions without writing to memory. Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel and gateway page execute at privilege level 0, so this code never triggers a read access interruption. Thus, it is currently possible for user code to execute a LWS compare and swap operation at an address that is read protected at privilege level 3 (PRIV_USER). Fix this by probing read access rights at privilege level 3 and branching to lws_fault if access isn't allowed.

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