openrisc: fix arbitrary kernel memory access via or1k_atomic syscall
Published Sep 11, 2026
7.8
HIGHCVSS 3.1
EPSS 0.14%
Description
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.
[shorne@gmail.com: fix comment style]
Affected products
-
Affected
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
-
Affected
- 3.1
Unaffected
- ≥ 0, < 3.1
- ≥ 5.10.270, ≤ 5.10.*
- ≥ 5.15.221, ≤ 5.15.*
- ≥ 6.1.188, ≤ 6.1.*
- ≥ 6.12.109, ≤ 6.12.*
- ≥ 6.18.50, ≤ 6.18.*
- ≥ 6.6.157, ≤ 6.6.*
- ≥ 7.2.4, ≤ 7.2.*
- 7.3-rc1
Default status is the baseline for the product. Each version can override it (patched versions can be marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| Linux | Linux | unaffected | Affected
|
| Linux | Linux | affected | Affected
Unaffected
|
No data.
No data.
Red Hat Enterprise Linux 10
kernel
Not affected
Red Hat Enterprise Linux 10
kernel-rt
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Not affected
Red Hat Enterprise Linux 9
kernel-rt
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-8
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-9
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 10 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (14)
- https://access.redhat.com/security/cve/CVE-2026-89489 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2532099 Issue Tracking
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-76395 Advisory
- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89489.mbox
- https://git.kernel.org/stable/c/1f2e92e499d863f81df1732af59b4a3559969193
- https://git.kernel.org/stable/c/497cba0b02e5555d99fe9ee1dc478af743ab7f7a
- https://git.kernel.org/stable/c/574ae2ac2b314aa33498cd2c28add106cbe644f2
- https://git.kernel.org/stable/c/78004e9a87f240df03e2f73120d291763c32e0a7
- https://git.kernel.org/stable/c/a520e8cac54fb403f3800125b606f55fcad42cb9
- https://git.kernel.org/stable/c/b53435c079c78f89f70a62dd5a322cca4e292b34
- https://git.kernel.org/stable/c/bf310718c6fa6adeee06d207a55489546d860e2c
- https://git.kernel.org/stable/c/d64a75369cd0f2ee79afcc9d9ca34a3890989379
- https://nvd.nist.gov/vuln/detail/CVE-2026-89489
- https://www.cve.org/CVERecord?id=CVE-2026-89489
Change history (0)
No recorded changes yet.
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