CVE-2023-52837 remediation guide

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: nbd: fix uaf in nbd_open Commit 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set disk->private_data as NULL as before. UAF may be triggered in nbd_open() if someone tries to open nbd device right after nbd_put() since nbd has been free in nbd_dev_remove(). Fix this by implementing ->free_disk and free private data in it.

Open CVE record

ProductLinux Linux, linux kernel

Affected versions>= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 4e9b3ec84dc97909876641dad14e0a2300d6c2a3, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 879947f4180bc6e83af64eb0515e0cf57fce15db, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 56bd7901b5e9dbc9112036ea615ebcba1565fafe, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 327462725b0f759f093788dfbcb2f1fd132f956b, >= 5.14, >= 5.14 < 6.1.63, >= 6.2 < 6.5.12, >= 6.6 < 6.6.2

Fixed versions6.1.63, 6.5.12, 6.6.2

Priority basisReview · CVSS 7.8 · EPSS 0.25%

Identify the affected asset

Confirm whether Linux Linux, linux kernel is installed, record the deployed version and installation path, and identify exposed interfaces.

Record the product name, package or appliance identifier, and installed version.
Identify internet-facing, administrative, API, and internal access paths.
Preserve the pre-change configuration and relevant service logs.

Validate the affected-version match

Compare the deployed version with the affected range: >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 4e9b3ec84dc97909876641dad14e0a2300d6c2a3, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 879947f4180bc6e83af64eb0515e0cf57fce15db, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 56bd7901b5e9dbc9112036ea615ebcba1565fafe, >= 4af5f2e0301311f88c420fcfc5f3c8611ade20ac < 327462725b0f759f093788dfbcb2f1fd132f956b, >= 5.14, >= 5.14 < 6.1.63, >= 6.2 < 6.5.12, >= 6.6 < 6.6.2. Treat incomplete inventory results as unresolved.

Prioritize with independent signals

The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

Apply supported remediation

Follow the vendor advisory or supported update path. Current fixed-version status: 6.1.63, 6.5.12, 6.6.2. Preserve configuration and rollback material before change.

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

Confirm the expected version and package state.
Run a functional health check for critical service paths.
Review authentication, error, application, and security monitoring logs.
Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.