CVE-2024-40951 ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger()

What is CVE-2024-40951?

CVE-2024-40951 is a medium-severity vulnerability in Linux kernel, published on 12 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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]

Weakness: CWE-476

Which versions are affected by CVE-2024-40951?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-40951?

Apply the vendor's patch.

Is CVE-2024-40951 being exploited?

There is no known exploitation of CVE-2024-40951 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-47433, BELL-CVE-2024-40951, DEBIAN-CVE-2024-40951, GHSA-86g8-833h-3hcm, UBUNTU-CVE-2024-40951.