PT-2026-26115 · Linux · Linux Kernel

Yin Fengwei

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Published

2026-01-01

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Updated

2026-05-21

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CVE-2026-23255

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 Linux kernel contains a flaw related to RCU (Read-Copy-Update) protection in the /proc/net/ptype interface. Specifically, the functions ptype seq next() and ptype seq show() do not adhere to RCU rules, potentially leading to RCU stalls. The issue arises because ptype seq show() reads pt->dev to obtain the device name without proper synchronization, while concurrent writers can remove packet type structures and clear pt->dev without an RCU grace period. The fix involves defining ptype iter state to carry a device pointer and adding full RCU protection to ptype seq next(), including the use of READ ONCE() when reading list.next values. A reproduction of the issue was provided by Dong Chenchen.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Race Condition

Weakness Enumeration

Related Identifiers

BDU:2026-04164
CVE-2026-23255
ECHO-1A4E-1FD9-0C85
OESA-2026-1862
OESA-2026-1863
OESA-2026-1864
OPENSUSE-SU-2026:20572-1
SUSE-SU-2026:1573-1
SUSE-SU-2026:1661-1
SUSE-SU-2026:21114-1
SUSE-SU-2026:21123-1
SUSE-SU-2026:21237-1
SUSE-SU-2026:21255-1
SUSE-SU-2026:21352-1
SUSE-SU-2026:21361-1

Affected Products

Linux Kernel