CVE-2021-47586 net: stmmac: dwmac-rk: fix oob read in rk_gmac_setup

What is CVE-2021-47586?

CVE-2021-47586 is a medium-severity memory corruption vulnerability in Linux kernel, published on 19 Jun 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:

net: stmmac: dwmac-rk: fix oob read in rk_gmac_setup

KASAN reports an out-of-bounds read in rk_gmac_setup on the line:

while (ops->regs[i]) {

This happens for most platforms since the regs flexible array member is empty, so the memory after the ops structure is being read here. It seems that mostly this happens to contain zero anyway, so we get lucky and everything still works.

To avoid adding redundant data to nearly all the ops structures, add a new flag to indicate whether the regs field is valid and avoid this loop when it is not.

Weakness: CWE-125

Which versions are affected by CVE-2021-47586?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47586?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-47586 being exploited?

There is no known exploitation of CVE-2021-47586 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-2021-47586, GHSA-89r8-fpgw-f2hq, UBUNTU-CVE-2021-47586.