# CVE-2026-74472: ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()

> A local attacker can trigger a kernel crash or leak process information by manipulating ublk device state fields during device addition.

- **Severity:** Not scored
- **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 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** BELL-CVE-2026-74472, DEBIAN-CVE-2026-74472, GHSA-7jg9-vhj9-wg56, UBUNTU-CVE-2026-74472

## What is CVE-2026-74472?

CVE-2026-74472 is a vulnerability in Linux, published on 15 Aug 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:

ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()

ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into
ub->dev_info and then fixes up the fields the driver owns, but misses
->state and ->ublksrv_pid.

A device added with ->state = UBLK_S_DEV_LIVE passes the
"->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its
proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV
right after ADD_DEV oopses in del_gendisk().  UBLK_S_DEV_QUIESCED plus
UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev().  A
poisoned ->state also gets START_USER_RECOVERY and the char device
read/write path onto a device that was never started, and wedges START_DEV
at -EEXIST.  A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an
unrelated task as the ublk server.

Reset both after the memcpy(), as ublk_detach_disk() does.  Userspace only
ever reads these back, so correcting them silently breaks nothing.

ADD_DEV has copied ->state in unsanitized since ublk was merged, but back
then it was harmless: the gendisk was allocated during ADD_DEV, and both
teardown and the START_DEV -EEXIST check keyed off disk_live() rather than
->state.  The oops became reachable once the disk allocation moved to
START_DEV and those checks switched to ->state.

## Which versions are affected by CVE-2026-74472?


## How do I fix CVE-2026-74472?

Apply the vendor's patch.

## Is CVE-2026-74472 being exploited?

There is no known exploitation of CVE-2026-74472 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74472 and fix it if it is affected.

What it is: CVE-2026-74472 is a vulnerability in Linux, published on 15 Aug 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-2026-74472 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-2026-74472/ (Markdown: https://insights.sbomify.com/CVE-2026-74472/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74472
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74472
- OSV: https://osv.dev/vulnerability/CVE-2026-74472

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74472/
Summaries are generated and may contain mistakes; the official description above is the record.