CVE-2021-47301 igb: Fix use-after-free error during reset

What is CVE-2021-47301?

CVE-2021-47301 is a high-severity use after free vulnerability in Linux kernel, published on 21 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:

igb: Fix use-after-free error during reset

Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring.

Failure to do so can cause invalid memory accesses. If igb_poll() runs while the controller is reset this can lead to the driver try to free a skb that was already freed.

(The crash is harder to reproduce with the igb driver, but the same potential problem exists as the code is identical to igc)

Weakness: CWE-416

Which versions are affected by CVE-2021-47301?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47301?

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-2021-47301 being exploited?

There is no known exploitation of CVE-2021-47301 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-2021-47301, GHSA-9h2q-cwg7-7wx8, UBUNTU-CVE-2021-47301.