---
id: CVE-2026-64423
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv4: igmp: remove multicast group from hash table on device destruction

  When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
  the multicast list…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv4: igmp: remove multicast group from hash table on device destruction

  When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
  the multicast list…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-416
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.11, < 5.10.261'
  - 'linux_kernel >= 5.11, < 5.15.212'
  - 'linux_kernel >= 5.16, < 6.1.178'
  - 'linux_kernel >= 6.2, < 6.6.145'
  - 'linux_kernel >= 6.7, < 6.12.96'
  - 'linux_kernel >= 6.13, < 6.18.39'
  - 'linux_kernel >= 6.19, < 7.1.4'
  - linux_kernel = 7.2
patched:
  - linux_kernel 7.1.4
published: '2026-07-25'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:19.463'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64423'
references:
  - url: 'https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00128
epssPercentile: 0.02781
ingestedAt: '2026-09-08T15:33:26.949Z'
---

## Overview

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

ipv4: igmp: remove multicast group from hash table on device destruction

When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
the multicast list and calls ip_ma_put() on each membership, scheduling
them for RCU reclamation. However, they are not unlinked from the device's
multicast hash table (mc_hash).

Since the device remains published in dev->ip_ptr until after
ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash
can still locate and access the multicast group after its refcount is
decremented. If the RCU callback runs and frees the group while a reader is
accessing it, a use-after-free occurs.

Fix this by unlinking the multicast group from mc_hash using
ip_mc_hash_remove() before scheduling it for reclamation.

BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0
Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276

Call Trace:
 <IRQ>
 dump_stack_lvl+0x67/0x90
 print_report+0x175/0x7c0
 kasan_report+0x147/0x180
 ip_check_mc_rcu+0x149/0x3f0
 udp_v4_early_demux+0x36d/0x12d0
 ip_rcv_finish_core+0xb8b/0x1390
 ip_rcv_finish+0x54/0x120
 NF_HOOK+0x213/0x2b0
 __netif_receive_skb+0x126/0x340
 process_backlog+0x4f2/0xf00
 __napi_poll+0x92/0x2c0
 net_rx_action+0x583/0xc60
 handle_softirqs+0x236/0x7f0
 do_softirq+0x57/0x80
 </IRQ>

Allocated by task 2239:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x72/0x90
 ____ip_mc_inc_group+0x31a/0xa40
 __ip_mc_join_group+0x334/0x3f0
 do_ip_setsockopt+0x16fa/0x2010
 ip_setsockopt+0x3f/0x90
 do_sock_setsockopt+0x1ad/0x300

Freed by task 0:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x3a/0x60
 __rcu_free_sheaf_prepare+0xd4/0x220
 rcu_free_sheaf+0x36/0x190
 rcu_core+0x8d9/0x12f0
 handle_softirqs+0x236/0x7f0

## Affected

- `linux_kernel >= 3.11, < 5.10.261`
- `linux_kernel >= 5.11, < 5.15.212`
- `linux_kernel >= 5.16, < 6.1.178`
- `linux_kernel >= 6.2, < 6.6.145`
- `linux_kernel >= 6.7, < 6.12.96`
- `linux_kernel >= 6.13, < 6.18.39`
- `linux_kernel >= 6.19, < 7.1.4`
- `linux_kernel = 7.2`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.1.4`