# CVE-2024-36930: spi: fix null pointer dereference within spi_sync

> A null pointer dereference in the Linux kernel SPI subsystem can cause a system crash when reusing SPI messages.

- **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:** 30 May 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-42459, BELL-CVE-2024-36930, DEBIAN-CVE-2024-36930, UBUNTU-CVE-2024-36930

## What is CVE-2024-36930?

CVE-2024-36930 is a medium-severity vulnerability in Linux kernel, published on 30 May 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:

spi: fix null pointer dereference within spi_sync

If spi_sync() is called with the non-empty queue and the same spi_message
is then reused, the complete callback for the message remains set while
the context is cleared, leading to a null pointer dereference when the
callback is invoked from spi_finalize_current_message().

With function inlining disabled, the call stack might look like this:

  _raw_spin_lock_irqsave from complete_with_flags+0x18/0x58
  complete_with_flags from spi_complete+0x8/0xc
  spi_complete from spi_finalize_current_message+0xec/0x184
  spi_finalize_current_message from spi_transfer_one_message+0x2a8/0x474
  spi_transfer_one_message from __spi_pump_transfer_message+0x104/0x230
  __spi_pump_transfer_message from __spi_transfer_message_noqueue+0x30/0xc4
  __spi_transfer_message_noqueue from __spi_sync+0x204/0x248
  __spi_sync from spi_sync+0x24/0x3c
  spi_sync from mcp251xfd_regmap_crc_read+0x124/0x28c [mcp251xfd]
  mcp251xfd_regmap_crc_read [mcp251xfd] from _regmap_raw_read+0xf8/0x154
  _regmap_raw_read from _regmap_bus_read+0x44/0x70
  _regmap_bus_read from _regmap_read+0x60/0xd8
  _regmap_read from regmap_read+0x3c/0x5c
  regmap_read from mcp251xfd_alloc_can_err_skb+0x1c/0x54 [mcp251xfd]
  mcp251xfd_alloc_can_err_skb [mcp251xfd] from mcp251xfd_irq+0x194/0xe70 [mcp251xfd]
  mcp251xfd_irq [mcp251xfd] from irq_thread_fn+0x1c/0x78
  irq_thread_fn from irq_thread+0x118/0x1f4
  irq_thread from kthread+0xd8/0xf4
  kthread from ret_from_fork+0x14/0x28

Fix this by also setting message->complete to NULL when the transfer is
complete.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-36930?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-36930?

Apply the vendor's patch.

## Is CVE-2024-36930 being exploited?

There is no known exploitation of CVE-2024-36930 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-2024-36930 and fix it if it is affected.

What it is: CVE-2024-36930 is a medium-severity vulnerability in Linux kernel, published on 30 May 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-2024-36930 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-2024-36930/ (Markdown: https://insights.sbomify.com/CVE-2024-36930/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36930
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36930
- OSV: https://osv.dev/vulnerability/CVE-2024-36930

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36930/
Summaries are generated and may contain mistakes; the official description above is the record.