CVE-2021-46973: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: Avoid potential use after free in MHI send It is possible that the MHI ul_callback will be invoked immediately following the queueing of the skb for transmission, leading to the callback decrementing the refcount of the associated sk and freeing the skb. As such the dereference of skb and the increment of the sk refcount must happen before the skb is queued, to avoid the skb to be used after free and potentially the sk to drop its last refcount..

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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	5.8 — 5.10.35
linux	linux_kernel	5.11 — 5.11.19
linux	linux_kernel	5.12 — 5.12.2

References

Advisories & Patches

https://git.kernel.org/stable/c/03c649dee8b1eb5600212a249542a70f47a5ab40 https://git.kernel.org/stable/c/47a017f33943278570c072bc71681809b2567b3a https://git.kernel.org/stable/c/48ec949ac979b4b42d740f67b6177797af834f80 https://git.kernel.org/stable/c/ea474054c2cc6e1284604b21361f475c7cc8c0a0 https://git.kernel.org/stable/c/03c649dee8b1eb5600212a249542a70f47a5ab40 https://git.kernel.org/stable/c/47a017f33943278570c072bc71681809b2567b3a https://git.kernel.org/stable/c/48ec949ac979b4b42d740f67b6177797af834f80 https://git.kernel.org/stable/c/ea474054c2cc6e1284604b21361f475c7cc8c0a0

Frequently Asked Questions

What is CVE-2021-46973? +

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: Avoid potential use after free in MHI send It is possible that the MHI ul_callback will be invoked immediately following the queueing of the skb for transmission, leading to the callback decrementing the refcount of the associated sk and freeing the skb. As such the dereference of skb and the increment of the sk refcount must happen before the skb is queued, to avoid the skb to be used after free and potentially the sk to drop its last refcount.. It has a CVSS v3.1 base score of 8.4 (HIGH).

How severe is CVE-2021-46973? +

CVE-2021-46973 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-2021-46973? +

CVE-2021-46973 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-2021-46973? +

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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