# CVE-2024-26740: net/sched: act_mirred: use the backlog for mirred ingress

> A race condition in the Linux kernel's network scheduler can cause a deadlock and system hang when redirecting network traffic.

- **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:** 3 Apr 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-58758, BELL-CVE-2024-26740, DEBIAN-CVE-2024-26740, GHSA-37h8-63p8-qhhg, ROOT-OS-DEBIAN-11-CVE-2024-26740, ROOT-OS-DEBIAN-12-CVE-2024-26740, ROOT-OS-UBUNTU-2204-CVE-2024-26740, UBUNTU-CVE-2024-26740

## What is CVE-2024-26740?

CVE-2024-26740 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 2024. 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:

net/sched: act_mirred: use the backlog for mirred ingress

The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog
for nested calls to mirred ingress") hangs our testing VMs every 10 or so
runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by
lockdep.

The problem as previously described by Davide (see Link) is that
if we reverse flow of traffic with the redirect (egress -> ingress)
we may reach the same socket which generated the packet. And we may
still be holding its socket lock. The common solution to such deadlocks
is to put the packet in the Rx backlog, rather than run the Rx path
inline. Do that for all egress -> ingress reversals, not just once
we started to nest mirred calls.

In the past there was a concern that the backlog indirection will
lead to loss of error reporting / less accurate stats. But the current
workaround does not seem to address the issue.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-26740?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-26740?

Apply the vendor's patch.

## Is CVE-2024-26740 being exploited?

There is no known exploitation of CVE-2024-26740 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-2024-26740 and fix it if it is affected.

What it is: CVE-2024-26740 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 2024. 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-2024-26740 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-2024-26740/ (Markdown: https://insights.sbomify.com/CVE-2024-26740/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26740
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26740
- OSV: https://osv.dev/vulnerability/CVE-2024-26740

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26740/
Summaries are generated and may contain mistakes; the official description above is the record.