# CVE-2024-56769: media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg

> An uninitialized memory read in the Linux kernel DVB frontend driver may allow local attackers to disclose sensitive kernel memory contents.

- **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:** 6 Jan 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-55056, AZL-55082, BELL-CVE-2024-56769, DEBIAN-CVE-2024-56769, GHSA-q23h-j65c-73m4, UBUNTU-CVE-2024-56769

## What is CVE-2024-56769?

CVE-2024-56769 is a medium-severity vulnerability in Linux kernel, published on 6 Jan 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:

media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg

Syzbot reports [1] an uninitialized value issue found by KMSAN in
dib3000_read_reg().

Local u8 rb[2] is used in i2c_transfer() as a read buffer; in case
that call fails, the buffer may end up with some undefined values.

Since no elaborate error handling is expected in dib3000_write_reg(),
simply zero out rb buffer to mitigate the problem.

[1] Syzkaller report
dvb-usb: bulk message failed: -22 (6/0)
=====================================================
BUG: KMSAN: uninit-value in dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
 dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
 dibusb_dib3000mb_frontend_attach+0x155/0x2f0 drivers/media/usb/dvb-usb/dibusb-mb.c:31
 dvb_usb_adapter_frontend_init+0xed/0x9a0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290
 dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:90 [inline]
 dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline]
 dvb_usb_device_init+0x25a8/0x3760 drivers/media/usb/dvb-usb/dvb-usb-init.c:310
 dibusb_probe+0x46/0x250 drivers/media/usb/dvb-usb/dibusb-mb.c:110
...
Local variable rb created at:
 dib3000_read_reg+0x86/0x4e0 drivers/media/dvb-frontends/dib3000mb.c:54
 dib3000mb_attach+0x123/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758
...

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2024-56769?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56769?

Apply the vendor's patch.

## Is CVE-2024-56769 being exploited?

There is no known exploitation of CVE-2024-56769 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-2024-56769 and fix it if it is affected.

What it is: CVE-2024-56769 is a medium-severity vulnerability in Linux kernel, published on 6 Jan 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-2024-56769 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-2024-56769/ (Markdown: https://insights.sbomify.com/CVE-2024-56769/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56769
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56769
- OSV: https://osv.dev/vulnerability/CVE-2024-56769

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56769/
Summaries are generated and may contain mistakes; the official description above is the record.