# CVE-2023-53236: iommufd: Do not corrupt the pfn list when doing batch carry

> A logic error in the Linux kernel iommufd subsystem causes page metadata corruption, potentially leading to system crashes or privilege escalation.

- **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:** 15 Sep 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-53236, DEBIAN-CVE-2023-53236, GHSA-f667-j8ph-5fg3, UBUNTU-CVE-2023-53236

## What is CVE-2023-53236?

CVE-2023-53236 is a high-severity memory corruption vulnerability in Linux kernel, published on 15 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: Do not corrupt the pfn list when doing batch carry

If batch->end is 0 then setting npfns[0] before computing the new value of
pfns will fail to adjust the pfn and result in various page accounting
corruptions. It should be ordered after.

This seems to result in various kinds of page meta-data corruption related
failures:

  WARNING: CPU: 1 PID: 527 at mm/gup.c:75 try_grab_folio+0x503/0x740
  Modules linked in:
  CPU: 1 PID: 527 Comm: repro Not tainted 6.3.0-rc2-eeac8ede1755+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:try_grab_folio+0x503/0x740
  Code: e3 01 48 89 de e8 6d c1 dd ff 48 85 db 0f 84 7c fe ff ff e8 4f bf dd ff 49 8d 47 ff 48 89 45 d0 e9 73 fe ff ff e8 3d bf dd ff <0f> 0b 31 db e9 d0 fc ff ff e8 2f bf dd ff 48 8b 5d c8 31 ff 48 89
  RSP: 0018:ffffc90000f37908 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: 00000000fffffc02 RCX: ffffffff81504c26
  RDX: 0000000000000000 RSI: ffff88800d030000 RDI: 0000000000000002
  RBP: ffffc90000f37948 R08: 000000000003ca24 R09: 0000000000000008
  R10: 000000000003ca00 R11: 0000000000000023 R12: ffffea000035d540
  R13: 0000000000000001 R14: 0000000000000000 R15: ffffea000035d540
  FS:  00007fecbf659740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000200011c3 CR3: 000000000ef66006 CR4: 0000000000770ee0
  PKRU: 55555554
  Call Trace:
   <TASK>
   internal_get_user_pages_fast+0xd32/0x2200
   pin_user_pages_fast+0x65/0x90
   pfn_reader_user_pin+0x376/0x390
   pfn_reader_next+0x14a/0x7b0
   pfn_reader_first+0x140/0x1b0
   iopt_area_fill_domain+0x74/0x210
   iopt_table_add_domain+0x30e/0x6e0
   iommufd_device_selftest_attach+0x7f/0x140
   iommufd_test+0x10ff/0x16f0
   iommufd_fops_ioctl+0x206/0x330
   __x64_sys_ioctl+0x10e/0x160
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

## Which versions are affected by CVE-2023-53236?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53236?

Apply the vendor's patch.

## Is CVE-2023-53236 being exploited?

There is no known exploitation of CVE-2023-53236 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-2023-53236 and fix it if it is affected.

What it is: CVE-2023-53236 is a high-severity memory corruption vulnerability in Linux kernel, published on 15 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-2023-53236 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-2023-53236/ (Markdown: https://insights.sbomify.com/CVE-2023-53236/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53236
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53236
- OSV: https://osv.dev/vulnerability/CVE-2023-53236

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53236/
Summaries are generated and may contain mistakes; the official description above is the record.