CVE-2025-39715

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> parisc: Revise gateway LWS calls to probe user read access<br /> <br /> We use load and stbys,e instructions to trigger memory reference<br /> interruptions without writing to memory. Because of the way read<br /> access support is implemented, read access interruptions are only<br /> triggered at privilege levels 2 and 3. The kernel and gateway<br /> page execute at privilege level 0, so this code never triggers<br /> a read access interruption. Thus, it is currently possible for<br /> user code to execute a LWS compare and swap operation at an<br /> address that is read protected at privilege level 3 (PRIV_USER).<br /> <br /> Fix this by probing read access rights at privilege level 3 and<br /> branching to lws_fault if access isn&amp;#39;t allowed.