Homepage
About Snyk

Use After Free Affecting kernel package, versions <0:4.14.238-182.421.amzn2

Severity

 Recommended
0.0
high
0
10

Based on Amazon Linux security rating

    Threat Intelligence

    EPSS
    0.04% (15th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk ID SNYK-AMZN2-KERNEL-7172195
  • published 31 May 2024
  • disclosed 28 Feb 2024
Report a new vulnerability Found a mistake?

Introduced: 28 Feb 2024

CVE-2021-47013 Open this link in a new tab
CWE-416 Open this link in a new tab

How to fix?

Upgrade Amazon-Linux:2 kernel to version 0:4.14.238-182.421.amzn2 or higher.
This issue was patched in ALAS2-2021-1685.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send

In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..). If some error happens in emac_tx_fill_tpd(), the skb will be freed via dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd(). But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len).

As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len, thus my patch assigns skb->len to 'len' before the possible free and use 'len' instead of skb->len later.

CVSS Scores

version 3.1
Expand this section

Red Hat

7 high
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    High
Expand this section

SUSE

5.5 medium