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Review reviewHigh

CVE-2021-47224

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: net: ll_temac: Make sure to free skb when it is completely used With the skb pointer piggy-backed on the TX BD, we have a simple and efficient way to free the skb buffer when the frame has been transmitted. But in order to avoid freeing the skb while there are still fragments from the skb in use, we need to piggy-back on the TX BD of the skb, not the first. Without this, we are doing use-after-free on the DMA side, when the first BD of a multi TX BD packet is seen as completed in xmit_done, and the remaining BDs are still b...

CVSS
7.8
EPSS
0.23%
14.1% percentile
CISA KEV
Not listed
Published
2024.05.22
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.23%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net: ll_temac: Make sure to free skb when it is completely used With the skb pointer piggy-backed on the TX BD, we have a simple and efficient way to free the skb buffer when the frame has been transmitted. But in order to avoid freeing the skb while there are still fragments from the skb in use, we need to piggy-back on the TX BD of the skb, not the first. Without this, we are doing use-after-free on the DMA side, when the first BD of a multi TX BD packet is seen as completed in xmit_done, and the remaining BDs are still b...

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
>= 92744989533cbe85e8057935d230e128810168ce < 6d120ab4dc39a543c6b63361e1d0541c382900a3, >= 92744989533cbe85e8057935d230e128810168ce < 019ab7d044d0ebf97e1236bb8935b7809be92358, >= 92744989533cbe85e8057935d230e128810168ce < e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b, >= 92744989533cbe85e8057935d230e128810168ce < 6aa32217a9a446275440ee8724b1ecaf1838df47, >= 2.6.31, < 5.4.128, >= 5.5 < 5.10.46, >= 5.11 < 5.12.13, 5.13
Fixed versions
5.4.128, 5.10.46, 5.12.13

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416