PT-2024-11209 · Linux+2 · Linux Kernel+2

Li Shuang

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Published

2021-05-17

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Updated

2025-01-08

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CVE-2021-47162

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description The issue arises when appending a fragment skb to a skb's frag list that already contains skbs from other sources. This can lead to use-after-free crashes, as the appended frag skb is seen by multiple skbs but only gets skb get called once. The problem occurs when a skb is created by pskb copy() where the frag list is cloned and shared among multiple skbs, or when a skb is updated by pskb may pull() with a skb cloned skb. Li Shuang has reported several crashes caused by this issue during testing on macvlan devices. The patch resolves this by linearizing the head skb if it has a frag list set in tipc buf append(), avoiding skb copy() by calling skb linearize() before skb unshare().
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Use After Free

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Weakness Enumeration

Related Identifiers

BDU:2025-13704
CVE-2021-47162
OESA-2024-1483
OESA-2024-1484
SUSE-SU-2024:1643-1
SUSE-SU-2024:1646-1
SUSE-SU-2024:1870-1
SUSE-SU-2024:1979-1
SUSE-SU-2024:1983-1
SUSE-SU-2024:2184-1
SUSE-SU-2024:4367-1
SUSE-SU-2024_4367-1
SUSE-SU-2025:0035-1
SUSE-SU-2025_0035-1

Affected Products

Astra Linux
Linux Kernel
Suse