# CVE-2022-49214: powerpc/64s: Don't use DSISR for SLB faults

> A Linux kernel bug on PowerPC 64s systems causes incorrect fault reporting for SLB faults, potentially leading to kernel crashes or denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49214, GHSA-8jrg-738q-v5mw, ROOT-OS-DEBIAN-11-CVE-2022-49214, UBUNTU-CVE-2022-49214

## What is CVE-2022-49214?

CVE-2022-49214 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

powerpc/64s: Don't use DSISR for SLB faults

Since commit 46ddcb3950a2 ("powerpc/mm: Show if a bad page fault on data
is read or write.") we use page_fault_is_write(regs->dsisr) in
__bad_page_fault() to determine if the fault is for a read or write, and
change the message printed accordingly.

But SLB faults, aka Data Segment Interrupts, don't set DSISR (Data
Storage Interrupt Status Register) to a useful value. All ISA versions
from v2.03 through v3.1 specify that the Data Segment Interrupt sets
DSISR "to an undefined value". As far as I can see there's no mention of
SLB faults setting DSISR in any BookIV content either.

This manifests as accesses that should be a read being incorrectly
reported as writes, for example, using the xmon "dump" command:

  0:mon> d 0x5deadbeef0000000
  5deadbeef0000000
  [359526.415354][    C6] BUG: Unable to handle kernel data access on write at 0x5deadbeef0000000
  [359526.415611][    C6] Faulting instruction address: 0xc00000000010a300
  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf400]
      pc: c00000000010a300: mread+0x90/0x190

If we disassemble the PC, we see a load instruction:

  0:mon> di c00000000010a300
  c00000000010a300 89490000      lbz     r10,0(r9)

We can also see in exceptions-64s.S that the data_access_slb block
doesn't set IDSISR=1, which means it doesn't load DSISR into pt_regs. So
the value we're using to determine if the fault is a read/write is some
stale value in pt_regs from a previous page fault.

Rework the printing logic to separate the SLB fault case out, and only
print read/write in the cases where we can determine it.

The result looks like eg:

  0:mon> d 0x5deadbeef0000000
  5deadbeef0000000
  [  721.779525][    C6] BUG: Unable to handle kernel data access at 0x5deadbeef0000000
  [  721.779697][    C6] Faulting instruction address: 0xc00000000014cbe0
  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]

  0:mon> d 0
  0000000000000000
  [  742.793242][    C6] BUG: Kernel NULL pointer dereference at 0x00000000
  [  742.793316][    C6] Faulting instruction address: 0xc00000000014cbe0
  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49214?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49214?

Apply the vendor's patch.

## Is CVE-2022-49214 being exploited?

There is no known exploitation of CVE-2022-49214 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-49214 and fix it if it is affected.

What it is: CVE-2022-49214 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-49214 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-49214/ (Markdown: https://insights.sbomify.com/CVE-2022-49214/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49214
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49214
- OSV: https://osv.dev/vulnerability/CVE-2022-49214

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49214/
Summaries are generated and may contain mistakes; the official description above is the record.