# CVE-2022-48795: parisc: Fix data TLB miss in sba_unmap_sg

> A null pointer dereference in the Linux kernel's parisc architecture driver causes a system crash, requiring a kernel patch.

- **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:** 16 Jul 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-48795, GHSA-6mpg-cp9m-pv2f, UBUNTU-CVE-2022-48795

## What is CVE-2022-48795?

CVE-2022-48795 is a medium-severity vulnerability in Linux kernel, published on 16 Jul 2024. 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:

parisc: Fix data TLB miss in sba_unmap_sg

Rolf Eike Beer reported the following bug:

[1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018
[1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4
[1274934.746891] Hardware name: 9000/785/C8000
[1274934.746891]
[1274934.746891]      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
[1274934.746891] PSW: 00001000000001001111111000001110 Not tainted
[1274934.746891] r00-03  000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000
[1274934.746891] r04-07  0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001
[1274934.746891] r08-11  0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001
[1274934.746891] r12-15  0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0
[1274934.746891] r16-19  0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007
[1274934.746891] r20-23  0000000000000006 000000004a368950 0000000000000000 0000000000000001
[1274934.746891] r24-27  0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0
[1274934.746891] r28-31  0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118
[1274934.746891] sr00-03  00000000066e5800 0000000000000000 0000000000000000 00000000066e5800
[1274934.746891] sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
[1274934.746891]
[1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec
[1274934.746891]  IIR: 48780030    ISR: 0000000000000000  IOR: 0000004140000018
[1274934.746891]  CPU:        3   CR30: 00000040e3a9c000 CR31: ffffffffffffffff
[1274934.746891]  ORIG_R28: 0000000040acdd58
[1274934.746891]  IAOQ[0]: sba_unmap_sg+0xb0/0x118
[1274934.746891]  IAOQ[1]: sba_unmap_sg+0xb4/0x118
[1274934.746891]  RP(r2): sba_unmap_sg+0xac/0x118
[1274934.746891] Backtrace:
[1274934.746891]  [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70
[1274934.746891]  [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60
[1274934.746891]  [<00000000407a3488>] mptscsih_io_done+0x150/0xd70
[1274934.746891]  [<0000000040798600>] mpt_interrupt+0x168/0xa68
[1274934.746891]  [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278
[1274934.746891]  [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8
[1274934.746891]  [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0
[1274934.746891]  [<00000000402548e0>] generic_handle_irq+0x50/0x70
[1274934.746891]  [<000000004019a254>] call_on_stack+0x18/0x24
[1274934.746891]
[1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?)

The bug is caused by overrunning the sglist and incorrectly testing
sg_dma_len(sglist) before nents. Normally this doesn't cause a crash,
but in this case sglist crossed a page boundary. This occurs in the
following code:

	while (sg_dma_len(sglist) && nents--) {

The fix is simply to test nents first and move the decrement of nents
into the loop.

## Which versions are affected by CVE-2022-48795?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-48795?

Apply the vendor's patch.

## Is CVE-2022-48795 being exploited?

There is no known exploitation of CVE-2022-48795 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-2022-48795 and fix it if it is affected.

What it is: CVE-2022-48795 is a medium-severity vulnerability in Linux kernel, published on 16 Jul 2024. 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-2022-48795 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-2022-48795/ (Markdown: https://insights.sbomify.com/CVE-2022-48795/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-48795
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-48795
- OSV: https://osv.dev/vulnerability/CVE-2022-48795

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-48795/
Summaries are generated and may contain mistakes; the official description above is the record.