# CVE-2026-74717: net/mlx5: fw_tracer, return NULL on create error

> A missing error check in the mlx5 network driver causes a kernel crash when tracer creation fails, 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:** 22 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97116, BELL-CVE-2026-74717, DEBIAN-CVE-2026-74717, GHSA-g47x-7cg4-hh99, UBUNTU-CVE-2026-74717

## What is CVE-2026-74717?

CVE-2026-74717 is a high-severity vulnerability in Linux, published on 22 Aug 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/mlx5: fw_tracer, return NULL on create error

Tracer creation can fail by returning either NULL or ERR_PTR.
The return value is stored without a check on the device, and users
treat ERR_PTR and NULL the same way.
This also causes a crash in the core dump logic, which is missing the
ERR_PTR check and ends up dereferencing it, as shown in the trace below.

Switch tracer creation to return NULL on failure only, so callers only
need a single NULL check.

  Internal error: Oops: 0000000096000006 [#1]  SMP
  Modules linked in: mlx5_ib ib_uverbs ib_core ipv6 mlx5_core
  CPU: 1 UID: 0 PID: 12 Comm: kworker/u16:0 Not tainted 6.19.7 #1 PREEMPT(none)
  Workqueue: mlx5_health0001:01:00.0 mlx5_fw_reporter_err_work [mlx5_core]
  pstate: a3400009 (NzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
  pc : mlx5_fw_tracer_trigger_core_dump_general+0x58/0xe0 [mlx5_core]
  lr : mlx5_fw_tracer_trigger_core_dump_general+0x40/0xe0 [mlx5_core]
  sp : ffff800081cf3c40
  x29: ffff800081cf3c90 x28: 0000000000000000 x27: 0000000000000000
  x26: ffff000080018828 x25: 0000000000000000 x24: ffff000080304a05
  x23: ffff800081cf3d80 x22: ffff0000847e01a0 x21: 0000000000000000
  x20: ffff0000847e01a0 x19: ffffffffffffffa1 x18: ffff80008310bbf0
  x17: ffff800080119650 x16: ffff80008010df54 x15: ffff80008010d4ac
  x14: ffff800079c202e4 x13: ffff80008002fe60 x12: ffff800080119650
  x11: ffff80008010df54 x10: ffff80008010d4ac x9 : ffff800079c203d8
  x8 : ffff800081cf3c88 x7 : 0000000000000000 x6 : 0000000000000000
  x5 : 0000000000000000 x4 : 0000000000000008 x3 : 0000000000000030
  x2 : 0000000000000008 x1 : 0000000000000000 x0 : 00000000c5c4000e
  Call trace:
   mlx5_fw_tracer_trigger_core_dump_general+0x58/0xe0 [mlx5_core] (P)
   mlx5_fw_reporter_dump+0x30/0x2e0 [mlx5_core]
   devlink_health_do_dump+0x9c/0x160
   devlink_health_report+0x1c0/0x288
   mlx5_fw_reporter_err_work+0xac/0xc0 [mlx5_core]
   process_one_work+0x15c/0x3d8
   worker_thread+0x18c/0x320
   kthread+0x148/0x228
   ret_from_fork+0x10/0x20
  Code: b9400000 5ac00800 7a401800 540003ca (3940a260)
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Oops: Fatal exception
  SMP: stopping secondary CPUs
  Kernel Offset: disabled
  CPU features: 0x000000,00078031,75fce5a1,35fffe67
  Memory Limit: none
  ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---

## Which versions are affected by CVE-2026-74717?


## How do I fix CVE-2026-74717?

Apply the vendor's patch.

## Is CVE-2026-74717 being exploited?

There is no known exploitation of CVE-2026-74717 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74717 and fix it if it is affected.

What it is: CVE-2026-74717 is a high-severity vulnerability in Linux, published on 22 Aug 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-2026-74717 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-2026-74717/ (Markdown: https://insights.sbomify.com/CVE-2026-74717/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74717
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74717
- OSV: https://osv.dev/vulnerability/CVE-2026-74717

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74717/
Summaries are generated and may contain mistakes; the official description above is the record.