CVE-2021-47480 scsi: core: Put LLD module refcnt after SCSI device is released

What is CVE-2021-47480?

CVE-2021-47480 is a medium-severity use after free vulnerability in Linux kernel, published on 22 May 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:

scsi: core: Put LLD module refcnt after SCSI device is released

SCSI host release is triggered when SCSI device is freed. We have to make sure that the low-level device driver module won't be unloaded before SCSI host instance is released because shost->hostt is required in the release handler.

Make sure to put LLD module refcnt after SCSI device is released.

Fixes a kernel panic of 'BUG: unable to handle page fault for address' reported by Changhui and Yi.

Which versions are affected by CVE-2021-47480?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47480?

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-2021-47480 being exploited?

There is no known exploitation of CVE-2021-47480 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 DEBIAN-CVE-2021-47480, GHSA-wc2g-rvvj-x242, UBUNTU-CVE-2021-47480.