CVE-2024-56764 ublk: detach gendisk from ublk device if add_disk() fails

What is CVE-2024-56764?

CVE-2024-56764 is a high-severity use after free vulnerability in Linux kernel, published on 6 Jan 2025. 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:

ublk: detach gendisk from ublk device if add_disk() fails

Inside ublk_abort_requests(), gendisk is grabbed for aborting all inflight requests. And ublk_abort_requests() is called when exiting the uring context or handling timeout.

If add_disk() fails, the gendisk may have been freed when calling ublk_abort_requests(), so use-after-free can be caused when getting disk's reference in ublk_abort_requests().

Fixes the bug by detaching gendisk from ublk device if add_disk() fails.

Weakness: CWE-416

Which versions are affected by CVE-2024-56764?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-56764?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2024-56764 being exploited?

There is no known exploitation of CVE-2024-56764 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 BELL-CVE-2024-56764, DEBIAN-CVE-2024-56764, GHSA-mq6g-3vj7-6g88, UBUNTU-CVE-2024-56764.