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

Vulnerability summary

CVE-2021-47586 is a medium (CVSS 5.5) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.9% of scored vulnerabilities.

Timeline

1. 19-06-2024
   PublishedVulnerability first disclosed.
2. 11-05-2026
   Last modifiedVulnerability information updated.

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.