# CVE-2023-53327: iommufd/selftest: Catch overflow of uptr and length

> An integer overflow in the Linux kernel iommufd selftest allows a local attacker to trigger a kernel warning and potential 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:** 16 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53327, DEBIAN-CVE-2023-53327, GHSA-5j3v-w49r-w347, UBUNTU-CVE-2023-53327

## What is CVE-2023-53327?

CVE-2023-53327 is a medium-severity vulnerability in Linux kernel, published on 16 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:

iommufd/selftest: Catch overflow of uptr and length

syzkaller hits a WARN_ON when trying to have a uptr close to UINTPTR_MAX:

  WARNING: CPU: 1 PID: 393 at drivers/iommu/iommufd/selftest.c:403 iommufd_test+0xb19/0x16f0
  Modules linked in:
  CPU: 1 PID: 393 Comm: repro Not tainted 6.2.0-c9c3395d5e3d #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:iommufd_test+0xb19/0x16f0
  Code: 94 c4 31 ff 44 89 e6 e8 a5 54 17 ff 45 84 e4 0f 85 bb 0b 00 00 41 be fb ff ff ff e8 31 53 17 ff e9 a0 f7 ff ff e8 27 53 17 ff <0f> 0b 41 be 8
  RSP: 0018:ffffc90000eabdc0 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8214c487
  RDX: 0000000000000000 RSI: ffff88800f5c8000 RDI: 0000000000000002
  RBP: ffffc90000eabe48 R08: 0000000000000000 R09: 0000000000000001
  R10: 0000000000000001 R11: 0000000000000000 R12: 00000000cd2b0000
  R13: 00000000cd2af000 R14: 0000000000000000 R15: ffffc90000eabe68
  FS:  00007f94d76d5740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020000043 CR3: 0000000006880006 CR4: 0000000000770ee0
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? write_comp_data+0x2f/0x90
   iommufd_fops_ioctl+0x1ef/0x310
   __x64_sys_ioctl+0x10e/0x160
   ? __pfx_iommufd_fops_ioctl+0x10/0x10
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

Check that the user memory range doesn't overflow.

## Which versions are affected by CVE-2023-53327?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53327?

Apply the vendor's patch.

## Is CVE-2023-53327 being exploited?

There is no known exploitation of CVE-2023-53327 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-2023-53327 and fix it if it is affected.

What it is: CVE-2023-53327 is a medium-severity vulnerability in Linux kernel, published on 16 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-2023-53327 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-2023-53327/ (Markdown: https://insights.sbomify.com/CVE-2023-53327/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53327
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53327
- OSV: https://osv.dev/vulnerability/CVE-2023-53327

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53327/
Summaries are generated and may contain mistakes; the official description above is the record.