# CVE-2026-93202: i3c: master: Fix recursive locking during device registration

> A recursive locking bug in the Linux kernel I3C master driver can cause a deadlock and system hang during device registration.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101906, BELL-CVE-2026-93202, DEBIAN-CVE-2026-93202, GHSA-w328-5f65-pqhc, UBUNTU-CVE-2026-93202

## What is CVE-2026-93202?

CVE-2026-93202 is a vulnerability in Linux, published on 17 Sep 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:

i3c: master: Fix recursive locking during device registration

i3c_master_register_new_i3c_devs() registers newly discovered devices
while holding i3c_bus_normaluse_lock(), a down_read().  device_register()
can immediately probe the device, and probe callbacks typically invoke
I3C helpers that take i3c_bus_normaluse_lock() again, leading to a
recursive acquisition of the same rwsem.  rwsems do not support recursive
read locking and can deadlock when a writer is waiting.  See the
"Recursive read locks" section of Documentation/locking/lockdep-design.rst.

For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like:
  # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind
  # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind
  WARNING: possible recursive locking detected
  kworker/5:1/94 is trying to acquire lock:
  ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370
  but task is already holding lock:
  ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0

Fix this by separating device creation from device registration.
Populate desc->dev under the maintenance lock, collect the devices that
still need registration into a local list, then release the lock before
calling device_register().  Finally retake the lock and clean up any
devices that failed to register.

Use the maintenance lock rather than the normal-use lock while adding
device objects.  A write-side maintenance lock prevents readers from
observing a partially initialized desc->dev during initial device
population, or desc->dev disappearing if registration fails.

The local list requires a list node, so add a list node member to struct
i3c_device.

## Which versions are affected by CVE-2026-93202?


## How do I fix CVE-2026-93202?

Apply the vendor's patch.

## Is CVE-2026-93202 being exploited?

There is no known exploitation of CVE-2026-93202 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93202 and fix it if it is affected.

What it is: CVE-2026-93202 is a vulnerability in Linux, published on 17 Sep 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-2026-93202 in the wild and no public exploit code.

Affected product: Linux. 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-2026-93202/ (Markdown: https://insights.sbomify.com/CVE-2026-93202/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93202
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93202
- OSV: https://osv.dev/vulnerability/CVE-2026-93202

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93202/
Summaries are generated and may contain mistakes; the official description above is the record.