# CVE-2026-23369: i2c: i801: Revert "i2c: i801: replace acpi_lock with I2C bus lock"

> A race condition in the i801 I2C driver causes a kernel NULL pointer dereference and panic during boot, leading to 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:** 25 Mar 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23369, DEBIAN-CVE-2026-23369, GHSA-vhcx-whwc-3wx5, ROOT-OS-DEBIAN-13-CVE-2026-23369, ROOT-OS-UBUNTU-2404-CVE-2026-23369, UBUNTU-CVE-2026-23369

## What is CVE-2026-23369?

CVE-2026-23369 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 2026. 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:

i2c: i801: Revert "i2c: i801: replace acpi_lock with I2C bus lock"

This reverts commit f707d6b9e7c18f669adfdb443906d46cfbaaa0c1.

Under rare circumstances, multiple udev threads can collect i801 device
info on boot and walk i801_acpi_io_handler somewhat concurrently. The
first will note the area is reserved by acpi to prevent further touches.
This ultimately causes the area to be deregistered. The second will
enter i801_acpi_io_handler after the area is unregistered but before a
check can be made that the area is unregistered. i2c_lock_bus relies on
the now unregistered area containing lock_ops to lock the bus. The end
result is a kernel panic on boot with the following backtrace;

[   14.971872] ioatdma 0000:09:00.2: enabling device (0100 -> 0102)
[   14.971873] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   14.971880] #PF: supervisor read access in kernel mode
[   14.971884] #PF: error_code(0x0000) - not-present page
[   14.971887] PGD 0 P4D 0
[   14.971894] Oops: 0000 [#1] PREEMPT SMP PTI
[   14.971900] CPU: 5 PID: 956 Comm: systemd-udevd Not tainted 5.14.0-611.5.1.el9_7.x86_64 #1
[   14.971905] Hardware name: XXXXXXXXXXXXXXXXXXXXXXX BIOS 1.20.10.SV91 01/30/2023
[   14.971908] RIP: 0010:i801_acpi_io_handler+0x2d/0xb0 [i2c_i801]
[   14.971929] Code: 00 00 49 8b 40 20 41 57 41 56 4d 8b b8 30 04 00 00 49 89 ce 41 55 41 89 d5 41 54 49 89 f4 be 02 00 00 00 55 4c 89 c5 53 89 fb <48> 8b 00 4c 89 c7 e8 18 61 54 e9 80 bd 80 04 00 00 00 75 09 4c 3b
[   14.971933] RSP: 0018:ffffbaa841483838 EFLAGS: 00010282
[   14.971938] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9685e01ba568
[   14.971941] RDX: 0000000000000008 RSI: 0000000000000002 RDI: 0000000000000000
[   14.971944] RBP: ffff9685ca22f028 R08: ffff9685ca22f028 R09: ffff9685ca22f028
[   14.971948] R10: 000000000000000b R11: 0000000000000580 R12: 0000000000000580
[   14.971951] R13: 0000000000000008 R14: ffff9685e01ba568 R15: ffff9685c222f000
[   14.971954] FS:  00007f8287c0ab40(0000) GS:ffff96a47f940000(0000) knlGS:0000000000000000
[   14.971959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   14.971963] CR2: 0000000000000000 CR3: 0000000168090001 CR4: 00000000003706f0
[   14.971966] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   14.971968] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   14.971972] Call Trace:
[   14.971977]  <TASK>
[   14.971981]  ? show_trace_log_lvl+0x1c4/0x2df
[   14.971994]  ? show_trace_log_lvl+0x1c4/0x2df
[   14.972003]  ? acpi_ev_address_space_dispatch+0x16e/0x3c0
[   14.972014]  ? __die_body.cold+0x8/0xd
[   14.972021]  ? page_fault_oops+0x132/0x170
[   14.972028]  ? exc_page_fault+0x61/0x150
[   14.972036]  ? asm_exc_page_fault+0x22/0x30
[   14.972045]  ? i801_acpi_io_handler+0x2d/0xb0 [i2c_i801]
[   14.972061]  acpi_ev_address_space_dispatch+0x16e/0x3c0
[   14.972069]  ? __pfx_i801_acpi_io_handler+0x10/0x10 [i2c_i801]
[   14.972085]  acpi_ex_access_region+0x5b/0xd0
[   14.972093]  acpi_ex_field_datum_io+0x73/0x2e0
[   14.972100]  acpi_ex_read_data_from_field+0x8e/0x230
[   14.972106]  acpi_ex_resolve_node_to_value+0x23d/0x310
[   14.972114]  acpi_ds_evaluate_name_path+0xad/0x110
[   14.972121]  acpi_ds_exec_end_op+0x321/0x510
[   14.972127]  acpi_ps_parse_loop+0xf7/0x680
[   14.972136]  acpi_ps_parse_aml+0x17a/0x3d0
[   14.972143]  acpi_ps_execute_method+0x137/0x270
[   14.972150]  acpi_ns_evaluate+0x1f4/0x2e0
[   14.972158]  acpi_evaluate_object+0x134/0x2f0
[   14.972164]  acpi_evaluate_integer+0x50/0xe0
[   14.972173]  ? vsnprintf+0x24b/0x570
[   14.972181]  acpi_ac_get_state.part.0+0x23/0x70
[   14.972189]  get_ac_property+0x4e/0x60
[   14.972195]  power_supply_show_property+0x90/0x1f0
[   14.972205]  add_prop_uevent+0x29/0x90
[   14.972213]  power_supply_uevent+0x109/0x1d0
[   14.972222]  dev_uevent+0x10e/0x2f0
[   14.972228]  uevent_show+0x8e/0x100
[   14.972236]  dev_attr_show+0x19
---truncated---

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-23369?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23369?

Apply the vendor's patch.

## Is CVE-2026-23369 being exploited?

There is no known exploitation of CVE-2026-23369 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-2026-23369 and fix it if it is affected.

What it is: CVE-2026-23369 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 2026. 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-2026-23369 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-2026-23369/ (Markdown: https://insights.sbomify.com/CVE-2026-23369/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23369
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23369
- OSV: https://osv.dev/vulnerability/CVE-2026-23369

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23369/
Summaries are generated and may contain mistakes; the official description above is the record.
