What’s Vulnerable › Vulnerabilities

CVE-2022-49921: net: sched: Fix use after free in red_enqueue()

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-05-01 · updated 2026-06-17
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: net: sched: Fix use after free in red_enqueue() We can't use "skb" again after passing it to qdisc_enqueue(). This is basically identical to commit 2f09707d0c97 ("sch_sfb: Also store skb len before calling child enqueue").

Affected products

• Linux kernel: from 4.4.163 before 4.5; from 4.7 before 4.9.333; from 4.10 before 4.14.299; from 4.15 before 4.19.265; from 4.20 before 5.4.224; from 5.5 before 5.10.154 — fixed in 4.14.299, 4.19.265, 4.5, 4.9.333, 5.10.154, 5.15.78

How to fix

Upgrade to a fixed version: Linux kernel 4.14.299, 4.19.265, 4.5, 4.9.333. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/170e5317042c302777ed6d59fdb84af9b0219d4e
• https://git.kernel.org/stable/c/52e0429471976785c155bfbf51d80990c6cd46e2
• https://git.kernel.org/stable/c/5960b9081baca85cc7dcb14aec1de85999ea9d36
• https://git.kernel.org/stable/c/795afe0b9bb6c915f0299a8e309936519be01619
• https://git.kernel.org/stable/c/8bdc2acd420c6f3dd1f1c78750ec989f02a1e2b9
• https://git.kernel.org/stable/c/a238cdcf2bdc72207c74375fc8be13ee549ca9db
• https://git.kernel.org/stable/c/e877f8fa49fbccc63cb2df2e9179bddc695b825a
• https://git.kernel.org/stable/c/fc4b50adb400ee5ec527a04073174e8e73a139fa

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