CVE-2025-39716

MEDIUM

Linux Kernel - Unauthenticated Unprotected Memory Read via __get_user()

Title source: llm
STIX 2.1

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.

Scores

CVSS v3 5.5
EPSS 0.0002
EPSS Percentile 5.1%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Details

Status published
Products (19)
debian/debian_linux 11.0
linux/Kernel 2.6.12 - 6.1.149linux
linux/Kernel 6.13.0 - 6.16.4linux
linux/Kernel 6.2.0 - 6.6.103linux
linux/Kernel 6.7.0 - 6.12.44linux
Linux/Linux < 2.6.12
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 28a9b71671fb4a2993ef85b8ef6f117ea63894fe
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 4c981077255acc2ed5b3df6e8dd0125c81b626a9
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 741b163e440683195b8fd4fc8495fcd0105c6ab7
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 89f686a0fb6e473a876a9a60a13aec67a62b9a7e
... and 9 more
Published Sep 05, 2025
Tracked Since Feb 18, 2026