CVE-2025-39715 — parisc: Revise gateway LWS calls to probe user read access
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 …
Published: 2025-09-05 · CVSS: Unscored
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7