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

2024-06-1914:53:51

Linux

www.cve.org

linux kernel

vulnerability

stmmac

dwmac-rk

oob read

rk_gmac_setup

kasan

out-of-bounds

memory

ops structure

redundant data

flag

0.0004 Low

EPSS

Percentile

9.1%

JSON

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-&gt;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.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c"
    ],
    "versions": [
      {
        "version": "3bb3d6b1c195",
        "lessThan": "0b4a5d1e15ce",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3bb3d6b1c195",
        "lessThan": "0546b224cc77",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c"
    ],
    "versions": [
      {
        "version": "5.14",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.14",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.11",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]