CVE-2021-47586: linux kernel Out-of-bounds Read — Fix

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.

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.14 — 5.15.11
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

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

Frequently Asked Questions

What is CVE-2021-47586? +

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. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-47586? +

CVE-2021-47586 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-47586? +

CVE-2021-47586 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-47586? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2021-47586