---
id: CVE-2026-72341
title: 'net/mlx5e: Fix publication race for priv->channel_stats[]'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/mlx5e: Fix publication race for priv->channel_stats[]

  mlx5e_channel_stats_alloc() publishes a new entry to
  priv->channel_stats[] and then increments priv->stats_nc…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 <
    268869794170af37727816ad02051808adb9c9c3
  - >-
    Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 <
    acd34d24342a28794e706ce8191ca6c3114a38ae
  - >-
    Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 <
    5c7e3755abf663f033de24f917b77685e9543045
  - >-
    Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 <
    815515ec68f527ca755cb1e2c1ff9148f6b3ea56
  - >-
    Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 <
    5a799714e8ca0bce9ea40694f49914cf1adbbaa9
  - Linux 5.17
published: '2026-08-15'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:44:38.498Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72341'
references:
  - url: 'https://git.kernel.org/stable/c/268869794170af37727816ad02051808adb9c9c3'
  - url: 'https://git.kernel.org/stable/c/acd34d24342a28794e706ce8191ca6c3114a38ae'
  - url: 'https://git.kernel.org/stable/c/5c7e3755abf663f033de24f917b77685e9543045'
  - url: 'https://git.kernel.org/stable/c/815515ec68f527ca755cb1e2c1ff9148f6b3ea56'
  - url: 'https://git.kernel.org/stable/c/5a799714e8ca0bce9ea40694f49914cf1adbbaa9'
tags:
  - cve.org
epss: 0.00206
epssPercentile: 0.10126
ingestedAt: '2026-10-21T12:48:53.591Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Fix publication race for priv->channel_stats[]

mlx5e_channel_stats_alloc() publishes a new entry to
priv->channel_stats[] and then increments priv->stats_nch as a
publication token, but neither store carries any memory barrier:

	priv->channel_stats[ix] = kvzalloc_node(...);
	if (!priv->channel_stats[ix])
		return -ENOMEM;
	priv->stats_nch++;

Concurrent readers compute the loop bound from priv->stats_nch and
then dereference priv->channel_stats[i] using plain accesses, e.g.

	for (i = 0; i < priv->stats_nch; i++) {
		struct mlx5e_channel_stats *cs = priv->channel_stats[i];
		... cs->rq.packets ...
	}

On weakly-ordered architectures (ARM, PowerPC, RISC-V) the writes to
channel_stats[ix] and stats_nch may become visible to other CPUs out
of program order. A reader can observe stats_nch == N while still
seeing channel_stats[N-1] == NULL, leading to a NULL pointer
dereference in the channel_stats loop.

This has been observed in production on BlueField-3 DPUs (arm64),
where ovs-vswitchd queries netdev statistics over netlink during NIC
bringup, racing mlx5e_open_channel() -> mlx5e_channel_stats_alloc()
on another CPU:

  Unable to handle kernel NULL pointer dereference at virtual address 0x840
  Hardware name: BlueField-3 DPU
  pc : mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]
  Call trace:
   mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]
   dev_get_stats+0x50/0xc0
   ovs_vport_get_stats+0x38/0xac [openvswitch]
   ovs_vport_cmd_fill_info+0x194/0x290 [openvswitch]
   ovs_vport_cmd_get+0xbc/0x10c [openvswitch]
   genl_family_rcv_msg_doit+0xd0/0x160
   genl_rcv_msg+0xec/0x1f0
   netlink_rcv_skb+0x64/0x130
   genl_rcv+0x40/0x60
   netlink_unicast+0x2fc/0x370
   netlink_sendmsg+0x1dc/0x454
   ...
   __arm64_sys_sendmsg+0x2c/0x40

Add mlx5e_stats_nch_write() and mlx5e_stats_nch_read() helpers in en.h
that wrap the smp_store_release()/smp_load_acquire() pair on stats_nch.
The release/acquire pair establishes the contract:

  stats_nch == N  =>  channel_stats[0..N-1] are visible and non-NULL.

Publish the stats_nch increment via mlx5e_stats_nch_write() in the
writer (mlx5e_channel_stats_alloc()), and read stats_nch via
mlx5e_stats_nch_read() in all readers: mlx5e RX/TX queue stats,
mlx5e_get_base_stats(), ethtool channels stats, IPoIB stats, the
sw_stats fold and the HV VHCA stats agent.

## Affected

- `Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 < 268869794170af37727816ad02051808adb9c9c3`
- `Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 < acd34d24342a28794e706ce8191ca6c3114a38ae`
- `Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 < 5c7e3755abf663f033de24f917b77685e9543045`
- `Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 < 815515ec68f527ca755cb1e2c1ff9148f6b3ea56`
- `Linux >= fa691d0c9c0812b9045f3a9420862e47b3b92518 < 5a799714e8ca0bce9ea40694f49914cf1adbbaa9`
- `Linux 5.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.