CVE-2025-39716

medium

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.

References

https://git.kernel.org/stable/c/f410ef9a032caf98117256b22139c31342d7bb06

https://git.kernel.org/stable/c/89f686a0fb6e473a876a9a60a13aec67a62b9a7e

https://git.kernel.org/stable/c/741b163e440683195b8fd4fc8495fcd0105c6ab7

https://git.kernel.org/stable/c/4c981077255acc2ed5b3df6e8dd0125c81b626a9

https://git.kernel.org/stable/c/28a9b71671fb4a2993ef85b8ef6f117ea63894fe

Details

Source: Mitre, NVD

Published: 2025-09-05

Updated: 2025-09-05

Risk Information

CVSS v2

Base Score: 1.7

Vector: CVSS2#AV:L/AC:L/Au:S/C:P/I:N/A:N

Severity: Low

CVSS v3

Base Score: 5.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

EPSS

EPSS: 0.00018