CVE-2024-40951: linux kernel Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger() bdev->bd_super has been removed and commit 8887b94d9322 change the usage from bdev->bd_super to b_assoc_map->host->i_sb. Since ocfs2 hasn't set bh->b_assoc_map, it will trigger NULL pointer dereference when calling into ocfs2_abort_trigger(). Actually this was pointed out in history, see commit 74e364ad1b13. But I've made a mistake when reviewing commit 8887b94d9322 and then re-introduce this regression. Since we cannot revive bdev in buffer head, so fix this issue by initializing all types of ocfs2 triggers when fill super, and then get the specific ocfs2 trigger from ocfs2_caching_info when access journal. [[email protected]: v2]

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CVSS v3.1 Score

5.5

MEDIUM

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

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.6 — 6.6.36
linux	linux_kernel	6.7 — 6.9.7
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/67bcecd780609f471260a8c83fb0ae15f27734ce https://git.kernel.org/stable/c/685d03c3795378fca6a1b3d43581f7f1a3fc095f https://git.kernel.org/stable/c/eb63357ef229fae061ce7ce2839d558681c42f1a https://git.kernel.org/stable/c/67bcecd780609f471260a8c83fb0ae15f27734ce https://git.kernel.org/stable/c/685d03c3795378fca6a1b3d43581f7f1a3fc095f https://git.kernel.org/stable/c/eb63357ef229fae061ce7ce2839d558681c42f1a

Frequently Asked Questions

What is CVE-2024-40951? +

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger() bdev->bd_super has been removed and commit 8887b94d9322 change the usage from bdev->bd_super to b_assoc_map->host->i_sb. Since ocfs2 hasn't set bh->b_assoc_map, it will trigger NULL pointer dereference when calling into ocfs2_abort_trigger(). Actually this was pointed out in history, see commit 74e364ad1b13. But I've made a mistake when reviewing commit 8887b94d9322 and then re-introduce this regression. Since we cannot revive bdev in buffer head, so fix this issue by initializing all types of ocfs2 triggers when fill super, and then get the specific ocfs2 trigger from ocfs2_caching_info when access journal. [[email protected]: v2] It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2024-40951? +

CVE-2024-40951 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-40951? +

CVE-2024-40951 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-2024-40951? +

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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