Cloudanix VulnDB

CVE-2026-23255

Medium · 5.5

CVSS

5.5

EPSS

0.1%

Published

Mar 18, 2026

CISA due date

—

The record

In the Linux kernel, the following vulnerability has been resolved: net: add proper RCU protection to /proc/net/ptype Yin Fengwei reported an RCU stall in ptype_seq_show() and provided a patch. Real issue is that ptype_seq_next() and ptype_seq_show() violate RCU rules. ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev to get device name without any barrier. At the same time, concurrent writers can remove a packet_type structure (which is correctly freed after an RCU grace period) and clear pt->dev without an RCU grace period. Define ptype_iter_state to carry a dev pointer along seq_net_private: struct ptype_iter_state { struct seq_net_private p; struct net_device *dev; // added in this patch }; We need to record the device pointer in ptype_get_idx() and ptype_seq_next() so that ptype_seq_show() is safe against concurrent pt->dev changes. We also need to add full RCU protection in ptype_seq_next(). (Missing READ_ONCE() when reading list.next values) Many thanks to Dong Chenchen for providing a repro.

Affected packages

Ecosystem Package Introduced Fixed
openSUSE:Leap 16.0 dtb-aarch64 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-64kb 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-azure 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-default 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-default-base 0 6.12.0-160000.27.1.160000.2.8
openSUSE:Leap 16.0 kernel-docs 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-kvmsmall 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-obs-build 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-obs-qa 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-rt 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-source 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-syms 0 6.12.0-160000.28.1
openSUSE:Leap 16.0 kernel-zfcpdump 0 6.12.0-160000.28.1

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