CVE-2021-47498 dm rq: don't queue request to blk-mq during DM suspend

What is CVE-2021-47498?

CVE-2021-47498 is a medium-severity denial of service 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:

dm rq: don't queue request to blk-mq during DM suspend

DM uses blk-mq's quiesce/unquiesce to stop/start device mapper queue.

But blk-mq's unquiesce may come from outside events, such as elevator switch, updating nr_requests or others, and request may come during suspend, so simply ask for blk-mq to requeue it.

Fixes one kernel panic issue when running updating nr_requests and dm-mpath suspend/resume stress test.

Which versions are affected by CVE-2021-47498?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47498?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-47498 being exploited?

There is no known exploitation of CVE-2021-47498 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-2021-47498, GHSA-78c9-2m2m-j8fh, ROOT-OS-DEBIAN-11-CVE-2021-47498, UBUNTU-CVE-2021-47498.