# CVE-2023-52506: LoongArch: Set all reserved memblocks on Node#0 at initialization

> A null pointer dereference in the Linux kernel LoongArch architecture causes a system panic during initialization when deferred struct page initialization is enabled.

- **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:** 2 Mar 2024
- **Updated:** 15 Aug 2026
- **Also known as:** BELL-CVE-2023-52506, DEBIAN-CVE-2023-52506, GHSA-98gp-w8mx-vgw9, UBUNTU-CVE-2023-52506

## What is CVE-2023-52506?

CVE-2023-52506 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:

LoongArch: Set all reserved memblocks on Node#0 at initialization

After commit 61167ad5fecdea ("mm: pass nid to reserve_bootmem_region()")
we get a panic if DEFERRED_STRUCT_PAGE_INIT is enabled:

[    0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000002b82, era == 90000000040e3f28, ra == 90000000040e3f18
[    0.000000] Oops[#1]:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0+ #733
[    0.000000] pc 90000000040e3f28 ra 90000000040e3f18 tp 90000000046f4000 sp 90000000046f7c90
[    0.000000] a0 0000000000000001 a1 0000000000200000 a2 0000000000000040 a3 90000000046f7ca0
[    0.000000] a4 90000000046f7ca4 a5 0000000000000000 a6 90000000046f7c38 a7 0000000000000000
[    0.000000] t0 0000000000000002 t1 9000000004b00ac8 t2 90000000040e3f18 t3 90000000040f0800
[    0.000000] t4 00000000000f0000 t5 80000000ffffe07e t6 0000000000000003 t7 900000047fff5e20
[    0.000000] t8 aaaaaaaaaaaaaaab u0 0000000000000018 s9 0000000000000000 s0 fffffefffe000000
[    0.000000] s1 0000000000000000 s2 0000000000000080 s3 0000000000000040 s4 0000000000000000
[    0.000000] s5 0000000000000000 s6 fffffefffe000000 s7 900000000470b740 s8 9000000004ad4000
[    0.000000]    ra: 90000000040e3f18 reserve_bootmem_region+0xec/0x21c
[    0.000000]   ERA: 90000000040e3f28 reserve_bootmem_region+0xfc/0x21c
[    0.000000]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
[    0.000000]  PRMD: 00000000 (PPLV0 -PIE -PWE)
[    0.000000]  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
[    0.000000]  ECFG: 00070800 (LIE=11 VS=7)
[    0.000000] ESTAT: 00010800 [PIL] (IS=11 ECode=1 EsubCode=0)
[    0.000000]  BADV: 0000000000002b82
[    0.000000]  PRID: 0014d000 (Loongson-64bit, Loongson-3A6000)
[    0.000000] Modules linked in:
[    0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____))
[    0.000000] Stack : 0000000000000000 9000000002eb5430 0000003a00000020 90000000045ccd00
[    0.000000]         900000000470e000 90000000002c1918 0000000000000000 9000000004110780
[    0.000000]         00000000fe6c0000 0000000480000000 9000000004b4e368 9000000004110748
[    0.000000]         0000000000000000 900000000421ca84 9000000004620000 9000000004564970
[    0.000000]         90000000046f7d78 9000000002cc9f70 90000000002c1918 900000000470e000
[    0.000000]         9000000004564970 90000000040bc0e0 90000000046f7d78 0000000000000000
[    0.000000]         0000000000004000 90000000045ccd00 0000000000000000 90000000002c1918
[    0.000000]         90000000002c1900 900000000470b700 9000000004b4df78 9000000004620000
[    0.000000]         90000000046200a8 90000000046200a8 0000000000000000 9000000004218b2c
[    0.000000]         9000000004270008 0000000000000001 0000000000000000 90000000045ccd00
[    0.000000]         ...
[    0.000000] Call Trace:
[    0.000000] [<90000000040e3f28>] reserve_bootmem_region+0xfc/0x21c
[    0.000000] [<900000000421ca84>] memblock_free_all+0x114/0x350
[    0.000000] [<9000000004218b2c>] mm_core_init+0x138/0x3cc
[    0.000000] [<9000000004200e38>] start_kernel+0x488/0x7a4
[    0.000000] [<90000000040df0d8>] kernel_entry+0xd8/0xdc
[    0.000000]
[    0.000000] Code: 02eb21ad  00410f4c  380c31ac <262b818d> 6800b70d  02c1c196  0015001c  57fe4bb1  260002cd

The reason is early memblock_reserve() in memblock_init() set node id to
MAX_NUMNODES, making NODE_DATA(nid) a NULL dereference in the call chain
reserve_bootmem_region() -> init_reserved_page(). After memblock_init(),
those late calls of memblock_reserve() operate on subregions of memblock
.memory regions. As a result, these reserved regions will be set to the
correct node at the first iteration of memmap_init_reserved_pages().

So set all reserved memblocks on Node#0 at initialization can avoid this
panic.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-52506?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52506?

Apply the vendor's patch.

## Is CVE-2023-52506 being exploited?

There is no known exploitation of CVE-2023-52506 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-2023-52506 and fix it if it is affected.

What it is: CVE-2023-52506 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-2023-52506 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-2023-52506/ (Markdown: https://insights.sbomify.com/CVE-2023-52506/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52506
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52506
- OSV: https://osv.dev/vulnerability/CVE-2023-52506

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52506/
Summaries are generated and may contain mistakes; the official description above is the record.
