# CVE-2024-53222: zram: fix NULL pointer in comp_algorithm_show()

> A local attacker can trigger a kernel crash by reading the zram sysfs interface before the compression algorithm is initialized.

- **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:** 27 Dec 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-55192, BELL-CVE-2024-53222, DEBIAN-CVE-2024-53222, GHSA-rxh5-6q4f-cfwp, UBUNTU-CVE-2024-53222

## What is CVE-2024-53222?

CVE-2024-53222 is a medium-severity vulnerability in Linux kernel, published on 27 Dec 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:

zram: fix NULL pointer in comp_algorithm_show()

LTP reported a NULL pointer dereference as followed:

 CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __pi_strcmp+0x24/0x140
 lr : zcomp_available_show+0x60/0x100 [zram]
 sp : ffff800088b93b90
 x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0
 x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000
 x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900
 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280
 x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000
 x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c
 x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000
 Call trace:
  __pi_strcmp+0x24/0x140
  comp_algorithm_show+0x40/0x70 [zram]
  dev_attr_show+0x28/0x80
  sysfs_kf_seq_show+0x90/0x140
  kernfs_seq_show+0x34/0x48
  seq_read_iter+0x1d4/0x4e8
  kernfs_fop_read_iter+0x40/0x58
  new_sync_read+0x9c/0x168
  vfs_read+0x1a8/0x1f8
  ksys_read+0x74/0x108
  __arm64_sys_read+0x24/0x38
  invoke_syscall+0x50/0x120
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x38/0x138
  el0t_64_sync_handler+0xc0/0xc8
  el0t_64_sync+0x188/0x190

The zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if
comp_algorithm_set() has not been called.  User can access the zram device
by sysfs after device_add_disk(), so there is a time window to trigger the
NULL pointer dereference.  Move it ahead device_add_disk() to make sure
when user can access the zram device, it is ready.  comp_algorithm_set()
is protected by zram->init_lock in other places and no such problem.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-53222?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-53222?

Apply the vendor's patch.

## Is CVE-2024-53222 being exploited?

There is no known exploitation of CVE-2024-53222 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-2024-53222 and fix it if it is affected.

What it is: CVE-2024-53222 is a medium-severity vulnerability in Linux kernel, published on 27 Dec 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-2024-53222 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-2024-53222/ (Markdown: https://insights.sbomify.com/CVE-2024-53222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-53222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-53222
- OSV: https://osv.dev/vulnerability/CVE-2024-53222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-53222/
Summaries are generated and may contain mistakes; the official description above is the record.