# CVE-2022-50751: configfs: fix possible memory leak in configfs_create_dir()

> A memory leak in the Linux kernel configfs subsystem can lead to resource exhaustion and denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50751, GHSA-7px2-rh6v-wcpc, UBUNTU-CVE-2022-50751

## What is CVE-2022-50751?

CVE-2022-50751 is a memory corruption vulnerability in Linux, published on 24 Dec 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:

configfs: fix possible memory leak in configfs_create_dir()

kmemleak reported memory leaks in configfs_create_dir():

unreferenced object 0xffff888009f6af00 (size 192):
  comm "modprobe", pid 3777, jiffies 4295537735 (age 233.784s)
  backtrace:
    kmem_cache_alloc (mm/slub.c:3250 mm/slub.c:3256 mm/slub.c:3263 mm/slub.c:3273)
    new_fragment (./include/linux/slab.h:600 fs/configfs/dir.c:163)
    configfs_register_subsystem (fs/configfs/dir.c:1857)
    basic_write (drivers/hwtracing/stm/p_basic.c:14) stm_p_basic
    do_one_initcall (init/main.c:1296)
    do_init_module (kernel/module/main.c:2455)
    ...

unreferenced object 0xffff888003ba7180 (size 96):
  comm "modprobe", pid 3777, jiffies 4295537735 (age 233.784s)
  backtrace:
    kmem_cache_alloc (mm/slub.c:3250 mm/slub.c:3256 mm/slub.c:3263 mm/slub.c:3273)
    configfs_new_dirent (./include/linux/slab.h:723 fs/configfs/dir.c:194)
    configfs_make_dirent (fs/configfs/dir.c:248)
    configfs_create_dir (fs/configfs/dir.c:296)
    configfs_attach_group.isra.28 (fs/configfs/dir.c:816 fs/configfs/dir.c:852)
    configfs_register_subsystem (fs/configfs/dir.c:1881)
    basic_write (drivers/hwtracing/stm/p_basic.c:14) stm_p_basic
    do_one_initcall (init/main.c:1296)
    do_init_module (kernel/module/main.c:2455)
    ...

This is because the refcount is not correct in configfs_make_dirent().
For normal stage, the refcount is changing as:

configfs_register_subsystem()
  configfs_create_dir()
    configfs_make_dirent()
      configfs_new_dirent() # set s_count = 1
      dentry->d_fsdata = configfs_get(sd); # s_count = 2
...
configfs_unregister_subsystem()
  configfs_remove_dir()
    remove_dir()
      configfs_remove_dirent() # s_count = 1
    dput() ...
      *dentry_unlink_inode()*
        configfs_d_iput() # s_count = 0, release

However, if we failed in configfs_create():

configfs_register_subsystem()
  configfs_create_dir()
    configfs_make_dirent() # s_count = 2
    ...
    configfs_create() # fail
    ->out_remove:
    configfs_remove_dirent(dentry)
      configfs_put(sd) # s_count = 1
      return PTR_ERR(inode);

There is no inode in the error path, so the configfs_d_iput() is lost
and makes sd and fragment memory leaked.

To fix this, when we failed in configfs_create(), manually call
configfs_put(sd) to keep the refcount correct.

## Which versions are affected by CVE-2022-50751?


## How do I fix CVE-2022-50751?

Apply the vendor's patch.

## Is CVE-2022-50751 being exploited?

There is no known exploitation of CVE-2022-50751 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50751 and fix it if it is affected.

What it is: CVE-2022-50751 is a memory corruption vulnerability in Linux, published on 24 Dec 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-2022-50751 in the wild and no public exploit code.

Affected product: Linux. 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-2022-50751/ (Markdown: https://insights.sbomify.com/CVE-2022-50751/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50751
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50751
- OSV: https://osv.dev/vulnerability/CVE-2022-50751

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50751/
Summaries are generated and may contain mistakes; the official description above is the record.