---
cve: "CVE-2026-23148"
severity: "HIGH"
cvss: 7.5
epss: "0.3%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-02-14 16:15:54"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T16:10:08+02:00"
---

# CVE-2026-23148

> 7.5 HIGH

## Beschreibung

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

nvmet: fix race in nvmet_bio_done() leading to NULL pointer dereference

There is a race condition in nvmet_bio_done() that can cause a NULL
pointer dereference in blk_cgroup_bio_start():

1. nvmet_bio_done() is called when a bio completes
2. nvmet_req_complete() is called, which invokes req->ops->queue_response(req)
3. The queue_response callback can re-queue and re-submit the same request
4. The re-submission reuses the same inline_bio from nvmet_req
5. Meanwhile, nvmet_req_bio_put() (called after nvmet_req_complete)
   invokes bio_uninit() for inline_bio, which sets bio->bi_blkg to NULL
6. The re-submitted bio enters submit_bio_noacct_nocheck()
7. blk_cgroup_bio_start() dereferences bio->bi_blkg, causing a crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000028
  #PF: supervisor read access in kernel mode
  RIP: 0010:blk_cgroup_bio_start+0x10/0xd0
  Call Trace:
   submit_bio_noacct_nocheck+0x44/0x250
   nvmet_bdev_execute_rw+0x254/0x370 [nvmet]
   process_one_work+0x193/0x3c0
   worker_thread+0x281/0x3a0

Fix this by reordering nvmet_bio_done() to call nvmet_req_bio_put()
BEFORE nvmet_req_complete(). This ensures the bio is cleaned up before
the request can be re-submitted, preventing the race condition.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.12.69
- Kernel ≥ 6.18.9

## Referenzen

- <https://git.kernel.org/stable/c/ee10b06980acca1d46e0fa36d6fb4a9578eab6e4>
- <https://git.kernel.org/stable/c/68207ceefd71cc74ce4e983fa9bd10c3122e349b>
- <https://git.kernel.org/stable/c/0fcee2cfc4b2e16e62ff8e0cc2cd8dd24efad65e>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-23148) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_