# CVE-2023-53576: null_blk: Always check queue mode setting from configfs

> A local attacker can cause a kernel crash by setting an invalid queue mode in the null_blk driver via configfs.

- **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:** 4 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53576, DEBIAN-CVE-2023-53576, GHSA-5h6w-mmcg-hf8j, UBUNTU-CVE-2023-53576

## What is CVE-2023-53576?

CVE-2023-53576 is a medium-severity vulnerability in Linux kernel, published on 4 Oct 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:

null_blk: Always check queue mode setting from configfs

Make sure to check device queue mode in the null_validate_conf() and
return error for NULL_Q_RQ as we don't allow legacy I/O path, without
this patch we get OOPs when queue mode is set to 1 from configfs,
following are repro steps :-

modprobe null_blk nr_devices=0
mkdir config/nullb/nullb0
echo 1 > config/nullb/nullb0/memory_backed
echo 4096 > config/nullb/nullb0/blocksize
echo 20480 > config/nullb/nullb0/size
echo 1 > config/nullb/nullb0/queue_mode
echo 1 > config/nullb/nullb0/power

Entering kdb (current=0xffff88810acdd080, pid 2372) on processor 42 Oops: (null)
due to oops @ 0xffffffffc041c329
CPU: 42 PID: 2372 Comm: sh Tainted: G           O     N 6.3.0-rc5lblk+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:null_add_dev.part.0+0xd9/0x720 [null_blk]
Code: 01 00 00 85 d2 0f 85 a1 03 00 00 48 83 bb 08 01 00 00 00 0f 85 f7 03 00 00 80 bb 62 01 00 00 00 48 8b 75 20 0f 85 6d 02 00 00 <48> 89 6e 60 48 8b 75 20 bf 06 00 00 00 e8 f5 37 2c c1 48 8b 75 20
RSP: 0018:ffffc900052cbde0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: ffff88811084d800 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888100042e00
RBP: ffff8881053d8200 R08: ffffc900052cbd68 R09: ffff888105db2000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: ffff888104765200 R14: ffff88810eec1748 R15: ffff88810eec1740
FS:  00007fd445fd1740(0000) GS:ffff8897dfc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 0000000166a00000 CR4: 0000000000350ee0
DR0: ffffffff8437a488 DR1: ffffffff8437a489 DR2: ffffffff8437a48a
DR3: ffffffff8437a48b DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nullb_device_power_store+0xd1/0x120 [null_blk]
 configfs_write_iter+0xb4/0x120
 vfs_write+0x2ba/0x3c0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fd4460c57a7
Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffd3792a4a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd4460c57a7
RDX: 0000000000000002 RSI: 000055b43c02e4c0 RDI: 0000000000000001
RBP: 000055b43c02e4c0 R08: 000000000000000a R09: 00007fd44615b4e0
R10: 00007fd44615b3e0 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fd446198520 R14: 0000000000000002 R15: 00007fd446198700
 </TASK>

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-53576?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53576?

Apply the vendor's patch.

## Is CVE-2023-53576 being exploited?

There is no known exploitation of CVE-2023-53576 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-2023-53576 and fix it if it is affected.

What it is: CVE-2023-53576 is a medium-severity vulnerability in Linux kernel, published on 4 Oct 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-2023-53576 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-2023-53576/ (Markdown: https://insights.sbomify.com/CVE-2023-53576/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53576
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53576
- OSV: https://osv.dev/vulnerability/CVE-2023-53576

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53576/
Summaries are generated and may contain mistakes; the official description above is the record.