# CVE-2024-50223: sched/numa: Fix the potential null pointer dereference in task_numa_work()

> A local attacker can trigger a kernel crash via a null pointer dereference in the NUMA scheduler, causing a 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:** 9 Nov 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-53072, BELL-CVE-2024-50223, DEBIAN-CVE-2024-50223, GHSA-x4h3-pqgr-cw5f, UBUNTU-CVE-2024-50223

## What is CVE-2024-50223?

CVE-2024-50223 is a medium-severity vulnerability in Linux kernel, published on 9 Nov 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:

sched/numa: Fix the potential null pointer dereference in task_numa_work()

When running stress-ng-vm-segv test, we found a null pointer dereference
error in task_numa_work(). Here is the backtrace:

  [323676.066985] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
  ......
  [323676.067108] CPU: 35 PID: 2694524 Comm: stress-ng-vm-se
  ......
  [323676.067113] pstate: 23401009 (nzCv daif +PAN -UAO +TCO +DIT +SSBS BTYPE=--)
  [323676.067115] pc : vma_migratable+0x1c/0xd0
  [323676.067122] lr : task_numa_work+0x1ec/0x4e0
  [323676.067127] sp : ffff8000ada73d20
  [323676.067128] x29: ffff8000ada73d20 x28: 0000000000000000 x27: 000000003e89f010
  [323676.067130] x26: 0000000000080000 x25: ffff800081b5c0d8 x24: ffff800081b27000
  [323676.067133] x23: 0000000000010000 x22: 0000000104d18cc0 x21: ffff0009f7158000
  [323676.067135] x20: 0000000000000000 x19: 0000000000000000 x18: ffff8000ada73db8
  [323676.067138] x17: 0001400000000000 x16: ffff800080df40b0 x15: 0000000000000035
  [323676.067140] x14: ffff8000ada73cc8 x13: 1fffe0017cc72001 x12: ffff8000ada73cc8
  [323676.067142] x11: ffff80008001160c x10: ffff000be639000c x9 : ffff8000800f4ba4
  [323676.067145] x8 : ffff000810375000 x7 : ffff8000ada73974 x6 : 0000000000000001
  [323676.067147] x5 : 0068000b33e26707 x4 : 0000000000000001 x3 : ffff0009f7158000
  [323676.067149] x2 : 0000000000000041 x1 : 0000000000004400 x0 : 0000000000000000
  [323676.067152] Call trace:
  [323676.067153]  vma_migratable+0x1c/0xd0
  [323676.067155]  task_numa_work+0x1ec/0x4e0
  [323676.067157]  task_work_run+0x78/0xd8
  [323676.067161]  do_notify_resume+0x1ec/0x290
  [323676.067163]  el0_svc+0x150/0x160
  [323676.067167]  el0t_64_sync_handler+0xf8/0x128
  [323676.067170]  el0t_64_sync+0x17c/0x180
  [323676.067173] Code: d2888001 910003fd f9000bf3 aa0003f3 (f9401000)
  [323676.067177] SMP: stopping secondary CPUs
  [323676.070184] Starting crashdump kernel...

stress-ng-vm-segv in stress-ng is used to stress test the SIGSEGV error
handling function of the system, which tries to cause a SIGSEGV error on
return from unmapping the whole address space of the child process.

Normally this program will not cause kernel crashes. But before the
munmap system call returns to user mode, a potential task_numa_work()
for numa balancing could be added and executed. In this scenario, since the
child process has no vma after munmap, the vma_next() in task_numa_work()
will return a null pointer even if the vma iterator restarts from 0.

Recheck the vma pointer before dereferencing it in task_numa_work().

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-50223?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-50223?

Apply the vendor's patch.

## Is CVE-2024-50223 being exploited?

There is no known exploitation of CVE-2024-50223 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-2024-50223 and fix it if it is affected.

What it is: CVE-2024-50223 is a medium-severity vulnerability in Linux kernel, published on 9 Nov 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-2024-50223 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-2024-50223/ (Markdown: https://insights.sbomify.com/CVE-2024-50223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-50223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-50223
- OSV: https://osv.dev/vulnerability/CVE-2024-50223

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-50223/
Summaries are generated and may contain mistakes; the official description above is the record.