# CVE-2022-49522: mmc: jz4740: Apply DMA engine limits to maximum segment size

> A missing DMA segment size limit in the Linux kernel MMC driver can trigger kernel warnings and potential instability when DMA API debugging is enabled.

- **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-2022-49522, GHSA-gqc7-5rv7-5pv6, UBUNTU-CVE-2022-49522

## What is CVE-2022-49522?

CVE-2022-49522 is a medium-severity denial of service 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:

mmc: jz4740: Apply DMA engine limits to maximum segment size

Do what is done in other DMA-enabled MMC host drivers (cf. host/mmci.c) and
limit the maximum segment size based on the DMA engine's capabilities. This
is needed to avoid warnings like the following with CONFIG_DMA_API_DEBUG=y.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 21 at kernel/dma/debug.c:1162 debug_dma_map_sg+0x2f4/0x39c
DMA-API: jz4780-dma 13420000.dma-controller: mapping sg segment longer than device claims to support [len=98304] [max=65536]
CPU: 0 PID: 21 Comm: kworker/0:1H Not tainted 5.18.0-rc1 #19
Workqueue: kblockd blk_mq_run_work_fn
Stack : 81575aec 00000004 80620000 80620000 80620000 805e7358 00000009 801537ac
        814c832c 806276e3 806e34b4 80620000 81575aec 00000001 81575ab8 09291444
        00000000 00000000 805e7358 81575958 ffffffea 8157596c 00000000 636f6c62
        6220646b 80387a70 0000000f 6d5f6b6c 80620000 00000000 81575ba4 00000009
        805e170c 80896640 00000001 00010000 00000000 00000000 00006098 806e0000
        ...
Call Trace:
[<80107670>] show_stack+0x84/0x120
[<80528cd8>] __warn+0xb8/0xec
[<80528d78>] warn_slowpath_fmt+0x6c/0xb8
[<8016f1d4>] debug_dma_map_sg+0x2f4/0x39c
[<80169d4c>] __dma_map_sg_attrs+0xf0/0x118
[<8016a27c>] dma_map_sg_attrs+0x14/0x28
[<804f66b4>] jz4740_mmc_prepare_dma_data+0x74/0xa4
[<804f6714>] jz4740_mmc_pre_request+0x30/0x54
[<804f4ff4>] mmc_blk_mq_issue_rq+0x6e0/0x7bc
[<804f5590>] mmc_mq_queue_rq+0x220/0x2d4
[<8038b2c0>] blk_mq_dispatch_rq_list+0x480/0x664
[<80391040>] blk_mq_do_dispatch_sched+0x2dc/0x370
[<80391468>] __blk_mq_sched_dispatch_requests+0xec/0x164
[<80391540>] blk_mq_sched_dispatch_requests+0x44/0x94
[<80387900>] __blk_mq_run_hw_queue+0xb0/0xcc
[<80134c14>] process_one_work+0x1b8/0x264
[<80134ff8>] worker_thread+0x2ec/0x3b8
[<8013b13c>] kthread+0x104/0x10c
[<80101dcc>] ret_from_kernel_thread+0x14/0x1c

---[ end trace 0000000000000000 ]---

## Which versions are affected by CVE-2022-49522?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49522?

Apply the vendor's patch.

## Is CVE-2022-49522 being exploited?

There is no known exploitation of CVE-2022-49522 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-2022-49522 and fix it if it is affected.

What it is: CVE-2022-49522 is a medium-severity denial of service 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-2022-49522 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-2022-49522/ (Markdown: https://insights.sbomify.com/CVE-2022-49522/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49522
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49522
- OSV: https://osv.dev/vulnerability/CVE-2022-49522

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49522/
Summaries are generated and may contain mistakes; the official description above is the record.