CVE-2026-89489

Status: UPDATED  |  Advisory ID: CVE-2026-89489

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

openrisc: fix arbitrary kernel memory access via or1k_atomic syscall

sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user

pointers, v1 and v2, and swaps the words they point to in hand-written

assembly.

l.lwz r29,0(r4)

l.lwz r27,0(r5)

l.sw 0(r4),r27

l.sw 0(r5),r29

The pointers are not checked with access_ok(). The four memory

accesses also have no exception table entries.

A caller passes a kernel address as either pointer, and the syscall

reads from and writes to it directly.

This gives an unprivileged process a kernel read/write primitive. It

overwrites kernel data such as the sys_call_table, gaining code

execution in kernel context.

Check both pointers before entering the critical section. Add fixups

for the four memory accesses so faults on valid but unmapped user

addresses return -EFAULT.

[[email protected]: fix comment style] (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References