Bug 2516814 (CVE-2026-74260)

Summary: CVE-2026-74260 kernel: netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's netfilter component, specifically within the nf_dup_netdev module. This vulnerability arises from an imbalanced decrementation of recursion counters when network packets are transmitted, particularly during a possible migration to a different CPU. This improper handling of recursion counters could lead to system instability or a denial of service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-08-15 06:34:51 UTC
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them

Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.
This patch also disables BH when transmitting the skb to address a
possible migration to different CPU leading to imbalanced decrementation
of the recursion counters.

This is modeled after Florian Westphal's dev_xmit_recursion*() API
available since commit 97cdcf37b57e ("net: place xmit recursion in
softnet data") according to its current state in the tree.