parisc: Revise __get_user() to probe user read access
At a glance
Severity
Not available
EPSS
EPSS 0.15 % · percentile 4 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified
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.
