# CVE-2023-54293: bcache: fixup btree_cache_wait list damage

> A use-after-free flaw in the Linux kernel bcache subsystem allows local attackers to cause a system crash via list corruption.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-54293, DEBIAN-CVE-2023-54293, GHSA-v9cw-759q-rvpj, UBUNTU-CVE-2023-54293

## What is CVE-2023-54293?

CVE-2023-54293 is an use after free vulnerability in Linux, published on 30 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:

bcache: fixup btree_cache_wait list damage

We get a kernel crash about "list_add corruption. next->prev should be
prev (ffff9c801bc01210), but was ffff9c77b688237c.
(next=ffffae586d8afe68)."

crash> struct list_head 0xffff9c801bc01210
struct list_head {
  next = 0xffffae586d8afe68,
  prev = 0xffffae586d8afe68
}
crash> struct list_head 0xffff9c77b688237c
struct list_head {
  next = 0x0,
  prev = 0x0
}
crash> struct list_head 0xffffae586d8afe68
struct list_head struct: invalid kernel virtual address: ffffae586d8afe68  type: "gdb_readmem_callback"
Cannot access memory at address 0xffffae586d8afe68

[230469.019492] Call Trace:
[230469.032041]  prepare_to_wait+0x8a/0xb0
[230469.044363]  ? bch_btree_keys_free+0x6c/0xc0 [escache]
[230469.056533]  mca_cannibalize_lock+0x72/0x90 [escache]
[230469.068788]  mca_alloc+0x2ae/0x450 [escache]
[230469.080790]  bch_btree_node_get+0x136/0x2d0 [escache]
[230469.092681]  bch_btree_check_thread+0x1e1/0x260 [escache]
[230469.104382]  ? finish_wait+0x80/0x80
[230469.115884]  ? bch_btree_check_recurse+0x1a0/0x1a0 [escache]
[230469.127259]  kthread+0x112/0x130
[230469.138448]  ? kthread_flush_work_fn+0x10/0x10
[230469.149477]  ret_from_fork+0x35/0x40

bch_btree_check_thread() and bch_dirty_init_thread() may call
mca_cannibalize() to cannibalize other cached btree nodes. Only one thread
can do it at a time, so the op of other threads will be added to the
btree_cache_wait list.

We must call finish_wait() to remove op from btree_cache_wait before free
it's memory address. Otherwise, the list will be damaged. Also should call
bch_cannibalize_unlock() to release the btree_cache_alloc_lock and wake_up
other waiters.

## Which versions are affected by CVE-2023-54293?


## How do I fix CVE-2023-54293?

Apply the vendor's patch.

## Is CVE-2023-54293 being exploited?

There is no known exploitation of CVE-2023-54293 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54293 and fix it if it is affected.

What it is: CVE-2023-54293 is an use after free vulnerability in Linux, published on 30 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-2023-54293 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-2023-54293/ (Markdown: https://insights.sbomify.com/CVE-2023-54293/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54293
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54293
- OSV: https://osv.dev/vulnerability/CVE-2023-54293

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54293/
Summaries are generated and may contain mistakes; the official description above is the record.