# CVE-2023-52568: x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race

> A race condition in the Linux kernel SGX subsystem causes a NULL pointer dereference, leading to a system crash.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/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:** 2 Mar 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-52568, DEBIAN-CVE-2023-52568, GHSA-mxqg-3qg8-9qfj, UBUNTU-CVE-2023-52568

## What is CVE-2023-52568?

CVE-2023-52568 is a medium-severity vulnerability in Linux kernel, published on 2 Mar 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:

x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race

The SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an
enclave and set secs.epc_page to NULL. The SECS page is used for EAUG
and ELDU in the SGX page fault handler. However, the NULL check for
secs.epc_page is only done for ELDU, not EAUG before being used.

Fix this by doing the same NULL check and reloading of the SECS page as
needed for both EAUG and ELDU.

The SECS page holds global enclave metadata. It can only be reclaimed
when there are no other enclave pages remaining. At that point,
virtually nothing can be done with the enclave until the SECS page is
paged back in.

An enclave can not run nor generate page faults without a resident SECS
page. But it is still possible for a #PF for a non-SECS page to race
with paging out the SECS page: when the last resident non-SECS page A
triggers a #PF in a non-resident page B, and then page A and the SECS
both are paged out before the #PF on B is handled.

Hitting this bug requires that race triggered with a #PF for EAUG.
Following is a trace when it happens.

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:sgx_encl_eaug_page+0xc7/0x210
Call Trace:
 ? __kmem_cache_alloc_node+0x16a/0x440
 ? xa_load+0x6e/0xa0
 sgx_vma_fault+0x119/0x230
 __do_fault+0x36/0x140
 do_fault+0x12f/0x400
 __handle_mm_fault+0x728/0x1110
 handle_mm_fault+0x105/0x310
 do_user_addr_fault+0x1ee/0x750
 ? __this_cpu_preempt_check+0x13/0x20
 exc_page_fault+0x76/0x180
 asm_exc_page_fault+0x27/0x30

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-52568?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52568?

Apply the vendor's patch.

## Is CVE-2023-52568 being exploited?

There is no known exploitation of CVE-2023-52568 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-2023-52568 and fix it if it is affected.

What it is: CVE-2023-52568 is a medium-severity vulnerability in Linux kernel, published on 2 Mar 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-2023-52568 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-2023-52568/ (Markdown: https://insights.sbomify.com/CVE-2023-52568/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52568
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52568
- OSV: https://osv.dev/vulnerability/CVE-2023-52568

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52568/
Summaries are generated and may contain mistakes; the official description above is the record.