CVE-2025-39716
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-05

Last updated on: 2025-11-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: parisc: Revise __get_user() to probe user read access Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel executes at privilege level 0, so __get_user() never triggers a read access interruption (code 26). Thus, it is currently possible for user code to access a read protected address via a system call. Fix this by probing read access rights at privilege level 3 (PRIV_USER) and setting __gu_err to -EFAULT (-14) if access isn't allowed. Note the cmpiclr instruction does a 32-bit compare because COND macro doesn't work inside asm.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-09-05
Last Modified
2025-11-03
Generated
2026-05-27
AI Q&A
2025-09-05
EPSS Evaluated
2026-05-25
NVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel 6.1.153-1
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's parisc architecture where the __get_user() function does not properly check read access permissions at the correct privilege level. Because read access interruptions are only triggered at privilege levels 2 and 3, and the kernel runs at privilege level 0, __get_user() fails to trigger a read access interruption when user code tries to read protected memory addresses via a system call. This allows user code to access read-protected addresses improperly. The fix involves probing read access rights at privilege level 3 and returning an error if access is not allowed.


How can this vulnerability impact me? :

This vulnerability can allow user-level code to read memory addresses that should be protected, potentially exposing sensitive kernel memory contents or other protected data. This unauthorized read access could lead to information disclosure or other security issues depending on what data is accessed.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart