# CVE-2026-80997: net: ipa: fix stalled modem TX queue after runtime resume

> A race condition in the Linux kernel IPA driver causes permanent network transmit stalls after runtime resume, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-80997, DEBIAN-CVE-2026-80997, GHSA-4hqp-w86v-96hh, UBUNTU-CVE-2026-80997

## What is CVE-2026-80997?

CVE-2026-80997 is a high-severity denial of service vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: ipa: fix stalled modem TX queue after runtime resume

ipa_start_xmit() unconditionally stops the TX queue before calling
pm_runtime_get(), relying on the wake scheduled by runtime resume
(ipa_modem_wake_queue_work()) to restart it once power is ACTIVE.
But that work is queued from within the runtime resume callback,
before the device's power state reaches RPM_ACTIVE, so it can run
while the device is still RPM_RESUMING.  The wake is then consumed
too early: the transmit it restarts stops the queue again,
pm_runtime_get() returns -EINPROGRESS without arranging any future
wake (deferred_resume exists only for RPM_SUSPENDING), and after the
resume completes nothing is left to wake the queue.  Transmit stalls
permanently: packets pile up in the qdisc behind the stopped queue,
the device runtime-suspends, and since the netdev registers no
ndo_tx_timeout the watchdog never fires.  Observed on SM7635
(Fairphone 6) as the cellular data path going permanently deaf
within hours, RX included, since nothing resumes the suspended
endpoints.

Close the window by making the wake work wait for the resume to
complete (pm_runtime_get_sync()) before waking the queue.  Every
queue stop is then guaranteed a later wake that happens while power
is ACTIVE; a transmit racing a new suspend/resume cycle re-schedules
the work.  If the device could not be resumed, wake the queue anyway
so pending packets are dropped by the transmit path rather than
stranded.

The STARTED power flag used to narrow this window: a wake running
before the transmit path's stop suppressed that stop, but only once,
as the flag was cleared by the first stop it absorbed.  Removing the
flag made a single transmit during an in-flight resume sufficient to
strand the queue, which is the form observed.

With an accelerated reproducer (autosuspend delay shortened to 5 ms,
~20 packets/s of TX), an unpatched kernel stalled three times in
230 s / 4380 packets; with this patch the same test ran 3601 s /
70298 packets without a stall.

## Which versions are affected by CVE-2026-80997?


## How do I fix CVE-2026-80997?

Apply the vendor's patch.

## Is CVE-2026-80997 being exploited?

There is no known exploitation of CVE-2026-80997 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80997 and fix it if it is affected.

What it is: CVE-2026-80997 is a high-severity denial of service vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80997 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-2026-80997/ (Markdown: https://insights.sbomify.com/CVE-2026-80997/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80997
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80997
- OSV: https://osv.dev/vulnerability/CVE-2026-80997

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80997/
Summaries are generated and may contain mistakes; the official description above is the record.