# CVE-2022-48649: mm/slab_common: fix possible double free of kmem_cache

> A race condition in the Linux kernel memory allocator can cause a double free, potentially allowing local attackers to execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 28 Apr 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-48649, GHSA-mcvj-6jjv-7hw9, UBUNTU-CVE-2022-48649

## What is CVE-2022-48649?

CVE-2022-48649 is a high-severity use after free vulnerability in Linux kernel, published on 28 Apr 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:

mm/slab_common: fix possible double free of kmem_cache

When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu'
kunit test case cause a use-after-free error:

  BUG: KASAN: use-after-free in kobject_del+0x14/0x30
  Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261

  CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G    B            N 6.0.0-rc5-next-20220916 #17
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x48
   print_address_description.constprop.0+0x87/0x2a5
   print_report+0x103/0x1ed
   kasan_report+0xb7/0x140
   kobject_del+0x14/0x30
   kmem_cache_destroy+0x130/0x170
   test_exit+0x1a/0x30
   kunit_try_run_case+0xad/0xc0
   kunit_generic_run_threadfn_adapter+0x26/0x50
   kthread+0x17b/0x1b0
   </TASK>

The cause is inside kmem_cache_destroy():

kmem_cache_destroy
    acquire lock/mutex
    shutdown_cache
        schedule_work(kmem_cache_release) (if RCU flag set)
    release lock/mutex
    kmem_cache_release (if RCU flag not set)

In some certain timing, the scheduled work could be run before
the next RCU flag checking, which can then get a wrong value
and lead to double kmem_cache_release().

Fix it by caching the RCU flag inside protected area, just like 'refcnt'

Weakness: CWE-416 (Use After Free), CWE-415 (Double Free)

## Which versions are affected by CVE-2022-48649?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-48649?

Apply the vendor's patch.

## Is CVE-2022-48649 being exploited?

There is no known exploitation of CVE-2022-48649 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-2022-48649 and fix it if it is affected.

What it is: CVE-2022-48649 is a high-severity use after free vulnerability in Linux kernel, published on 28 Apr 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-2022-48649 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-2022-48649/ (Markdown: https://insights.sbomify.com/CVE-2022-48649/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-48649
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-48649
- OSV: https://osv.dev/vulnerability/CVE-2022-48649

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-48649/
Summaries are generated and may contain mistakes; the official description above is the record.