# CVE-2023-53231: erofs: Fix detection of atomic context

> A bug in the Linux kernel's EROFS filesystem causes a kernel panic when decompression occurs in an atomic context, leading to 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:** 15 Sep 2025
- **Updated:** 3 Oct 2026
- **Also known as:** BELL-CVE-2023-53231, DEBIAN-CVE-2023-53231, GHSA-72rq-7p7f-9f9j, ROOT-OS-DEBIAN-11-CVE-2023-53231, ROOT-OS-DEBIAN-12-CVE-2023-53231, ROOT-OS-UBUNTU-2204-CVE-2023-53231, UBUNTU-CVE-2023-53231

## What is CVE-2023-53231?

CVE-2023-53231 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 Sep 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:

erofs: Fix detection of atomic context

Current check for atomic context is not sufficient as
z_erofs_decompressqueue_endio can be called under rcu lock
from blk_mq_flush_plug_list(). See the stacktrace [1]

In such case we should hand off the decompression work for async
processing rather than trying to do sync decompression in current
context. Patch fixes the detection by checking for
rcu_read_lock_any_held() and while at it use more appropriate
!in_task() check than in_atomic().

Background: Historically erofs would always schedule a kworker for
decompression which would incur the scheduling cost regardless of
the context. But z_erofs_decompressqueue_endio() may not always
be in atomic context and we could actually benefit from doing the
decompression in z_erofs_decompressqueue_endio() if we are in
thread context, for example when running with dm-verity.
This optimization was later added in patch [2] which has shown
improvement in performance benchmarks.

==============================================
[1] Problem stacktrace
[name:core&]BUG: sleeping function called from invalid context at kernel/locking/mutex.c:291
[name:core&]in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1615, name: CpuMonitorServi
[name:core&]preempt_count: 0, expected: 0
[name:core&]RCU nest depth: 1, expected: 0
CPU: 7 PID: 1615 Comm: CpuMonitorServi Tainted: G S      W  OE      6.1.25-android14-5-maybe-dirty-mainline #1
Hardware name: MT6897 (DT)
Call trace:
 dump_backtrace+0x108/0x15c
 show_stack+0x20/0x30
 dump_stack_lvl+0x6c/0x8c
 dump_stack+0x20/0x48
 __might_resched+0x1fc/0x308
 __might_sleep+0x50/0x88
 mutex_lock+0x2c/0x110
 z_erofs_decompress_queue+0x11c/0xc10
 z_erofs_decompress_kickoff+0x110/0x1a4
 z_erofs_decompressqueue_endio+0x154/0x180
 bio_endio+0x1b0/0x1d8
 __dm_io_complete+0x22c/0x280
 clone_endio+0xe4/0x280
 bio_endio+0x1b0/0x1d8
 blk_update_request+0x138/0x3a4
 blk_mq_plug_issue_direct+0xd4/0x19c
 blk_mq_flush_plug_list+0x2b0/0x354
 __blk_flush_plug+0x110/0x160
 blk_finish_plug+0x30/0x4c
 read_pages+0x2fc/0x370
 page_cache_ra_unbounded+0xa4/0x23c
 page_cache_ra_order+0x290/0x320
 do_sync_mmap_readahead+0x108/0x2c0
 filemap_fault+0x19c/0x52c
 __do_fault+0xc4/0x114
 handle_mm_fault+0x5b4/0x1168
 do_page_fault+0x338/0x4b4
 do_translation_fault+0x40/0x60
 do_mem_abort+0x60/0xc8
 el0_da+0x4c/0xe0
 el0t_64_sync_handler+0xd4/0xfc
 el0t_64_sync+0x1a0/0x1a4

[2] Link: https://lore.kernel.org/all/20210317035448.13921-1-huangjianan@oppo.com/

## Which versions are affected by CVE-2023-53231?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53231?

Apply the vendor's patch.

## Is CVE-2023-53231 being exploited?

There is no known exploitation of CVE-2023-53231 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-2023-53231 and fix it if it is affected.

What it is: CVE-2023-53231 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 Sep 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-2023-53231 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-2023-53231/ (Markdown: https://insights.sbomify.com/CVE-2023-53231/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53231
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53231
- OSV: https://osv.dev/vulnerability/CVE-2023-53231

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53231/
Summaries are generated and may contain mistakes; the official description above is the record.
