CVE-2021-47586 Information

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.

Reference

https://git.kernel.org/stable/c/0b4a5d1e15ce72f69be48f38dc0401dab890ae0f https://git.kernel.org/stable/c/0546b224cc7717cc8a2db076b0bb069a9c430794