CVE-2021-47232: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: can: j1939: fix Use-after-Free, hold skb ref while in use This patch fixes a Use-after-Free found by the syzbot. The problem is that a skb is taken from the per-session skb queue, without incrementing the ref count. This leads to a Use-after-Free if the skb is taken concurrently from the session queue due to a CTS.

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CVSS v3.1 Score

8.4

HIGH

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

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.4 — 5.4.128
linux	linux_kernel	5.5 — 5.10.46
linux	linux_kernel	5.11 — 5.12.13
linux	linux_kernel	All
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/1071065eeb33d32b7d98c2ce7591881ae7381705 https://git.kernel.org/stable/c/2030043e616cab40f510299f09b636285e0a3678 https://git.kernel.org/stable/c/22cba878abf646cd3a02ee7c8c2cef7afe66a256 https://git.kernel.org/stable/c/509ab6bfdd0c76daebbad0f0af07da712116de22 https://git.kernel.org/stable/c/1071065eeb33d32b7d98c2ce7591881ae7381705 https://git.kernel.org/stable/c/2030043e616cab40f510299f09b636285e0a3678 https://git.kernel.org/stable/c/22cba878abf646cd3a02ee7c8c2cef7afe66a256 https://git.kernel.org/stable/c/509ab6bfdd0c76daebbad0f0af07da712116de22

Frequently Asked Questions

What is CVE-2021-47232? +

In the Linux kernel, the following vulnerability has been resolved: can: j1939: fix Use-after-Free, hold skb ref while in use This patch fixes a Use-after-Free found by the syzbot. The problem is that a skb is taken from the per-session skb queue, without incrementing the ref count. This leads to a Use-after-Free if the skb is taken concurrently from the session queue due to a CTS. It has a CVSS v3.1 base score of 8.4 (HIGH).

How severe is CVE-2021-47232? +

CVE-2021-47232 has a CVSS v3.1 score of 8.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2021-47232? +

CVE-2021-47232 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-2021-47232? +

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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