NULL Pointer Dereference Affecting kernel-uek-doc package, versions <0:6.12.0-200.74.27.el9uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.04% (11th percentile)

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  • Snyk IDSNYK-ORACLE9-KERNELUEKDOC-15865976
  • published1 Apr 2026
  • disclosed14 Feb 2026

Introduced: 14 Feb 2026

CVE-2026-23148  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Oracle:9 kernel-uek-doc to version 0:6.12.0-200.74.27.el9uek or higher.
This issue was patched in ELSA-2026-50160.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-uek-doc package and not the kernel-uek-doc package as distributed by Oracle. See How to fix? for Oracle:9 relevant fixed versions and status.

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 Base Scores

version 3.1