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

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-06-19 · updated 2026-06-17
Weakness: CWE-125

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.

Affected products

Linux kernel: from 5.14 before 5.15.11; 5.16-rc1, 5.16-rc2, 5.16-rc3, 5.16-rc4, 5.16-rc5 — fixed in 5.15.11

How to fix

Upgrade to a fixed version: Linux kernel 5.15.11. Check the vendor advisory for mitigations.

References

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