CVE-2023-52837: linux kernel Use-After-Free — Fix

Description

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.

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CVSS v3.1 Score

7.8

HIGH

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

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.14 — 6.1.63
linux	linux_kernel	6.2 — 6.5.12
linux	linux_kernel	6.6 — 6.6.2

References

Advisories & Patches

https://git.kernel.org/stable/c/327462725b0f759f093788dfbcb2f1fd132f956b https://git.kernel.org/stable/c/4e9b3ec84dc97909876641dad14e0a2300d6c2a3 https://git.kernel.org/stable/c/56bd7901b5e9dbc9112036ea615ebcba1565fafe https://git.kernel.org/stable/c/879947f4180bc6e83af64eb0515e0cf57fce15db https://git.kernel.org/stable/c/327462725b0f759f093788dfbcb2f1fd132f956b https://git.kernel.org/stable/c/4e9b3ec84dc97909876641dad14e0a2300d6c2a3 https://git.kernel.org/stable/c/56bd7901b5e9dbc9112036ea615ebcba1565fafe https://git.kernel.org/stable/c/879947f4180bc6e83af64eb0515e0cf57fce15db

Frequently Asked Questions

What is CVE-2023-52837? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-52837? +

CVE-2023-52837 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-52837? +

CVE-2023-52837 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-52837? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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