# CVE-2024-50182: secretmem: disable memfd_secret() if arch cannot set direct map

> Attackers can bypass memory secrecy protections on specific ARM64 configurations where direct map removal fails silently, exposing sensitive data.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **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:** 8 Nov 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-53772, BELL-CVE-2024-50182, DEBIAN-CVE-2024-50182, GHSA-9fq4-227m-74p5, UBUNTU-CVE-2024-50182

## What is CVE-2024-50182?

CVE-2024-50182 is a high-severity vulnerability in Linux kernel, published on 8 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:

secretmem: disable memfd_secret() if arch cannot set direct map

Return -ENOSYS from memfd_secret() syscall if !can_set_direct_map().  This
is the case for example on some arm64 configurations, where marking 4k
PTEs in the direct map not present can only be done if the direct map is
set up at 4k granularity in the first place (as ARM's break-before-make
semantics do not easily allow breaking apart large/gigantic pages).

More precisely, on arm64 systems with !can_set_direct_map(),
set_direct_map_invalid_noflush() is a no-op, however it returns success
(0) instead of an error.  This means that memfd_secret will seemingly
"work" (e.g.  syscall succeeds, you can mmap the fd and fault in pages),
but it does not actually achieve its goal of removing its memory from the
direct map.

Note that with this patch, memfd_secret() will start erroring on systems
where can_set_direct_map() returns false (arm64 with
CONFIG_RODATA_FULL_DEFAULT_ENABLED=n, CONFIG_DEBUG_PAGEALLOC=n and
CONFIG_KFENCE=n), but that still seems better than the current silent
failure.  Since CONFIG_RODATA_FULL_DEFAULT_ENABLED defaults to 'y', most
arm64 systems actually have a working memfd_secret() and aren't be
affected.

From going through the iterations of the original memfd_secret patch
series, it seems that disabling the syscall in these scenarios was the
intended behavior [1] (preferred over having
set_direct_map_invalid_noflush return an error as that would result in
SIGBUSes at page-fault time), however the check for it got dropped between
v16 [2] and v17 [3], when secretmem moved away from CMA allocations.

[1]: https://lore.kernel.org/lkml/20201124164930.GK8537@kernel.org/
[2]: https://lore.kernel.org/lkml/20210121122723.3446-11-rppt@kernel.org/#t
[3]: https://lore.kernel.org/lkml/20201125092208.12544-10-rppt@kernel.org/

## Which versions are affected by CVE-2024-50182?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-50182?

Apply the vendor's patch.

## Is CVE-2024-50182 being exploited?

There is no known exploitation of CVE-2024-50182 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-2024-50182 and fix it if it is affected.

What it is: CVE-2024-50182 is a high-severity vulnerability in Linux kernel, published on 8 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-2024-50182 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-2024-50182/ (Markdown: https://insights.sbomify.com/CVE-2024-50182/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-50182
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-50182
- OSV: https://osv.dev/vulnerability/CVE-2024-50182

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-50182/
Summaries are generated and may contain mistakes; the official description above is the record.