---
id: CVE-2025-38727
title: 'netlink: avoid infinite retry looping in netlink_unicast()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netlink: avoid infinite retry looping in netlink_unicast()

  netlink_attachskb() checks for the socket's read memory allocation
  constraints. Firstly, it has:

    rmem < R…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 9da025150b7c14a8390fc06aea314c0a4011e82c <
    47d49fd07f86d1f55ea1083287303d237e9e0922
  - >-
    Linux >= c4ceaac5c5ba0b992ee1dc88e2a02421549e5c98 <
    6bee383ff83352a693d03efdf27cdd80742f71b2
  - >-
    Linux >= fd69af06101090eaa60b3d216ae715f9c0a58e5b <
    f324959ad47e62e3cadaffa65d3cff790fb48529
  - >-
    Linux >= 76602d8e13864524382b0687dc32cd8f19164d5a <
    d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e
  - >-
    Linux >= 55baecb9eb90238f60a8350660d6762046ebd3bd <
    346c820ef5135cf062fa3473da955ef8c5fb6929
  - >-
    Linux >= 4b8e18af7bea92f8b7fb92d40aeae729209db250 <
    44ddd7b1ae0b7edb2c832eb16798c827a05e58f0
  - >-
    Linux >= cd7ff61bfffd7000143c42bbffb85eeb792466d6 <
    78fcd69d55c5f11d7694c547eca767a1cfd38ec4
  - >-
    Linux >= ae8f160e7eb24240a2a79fc4c815c6a0d4ee16cc <
    e8edc7de688791a337c068693f22e8d8b869df71
  - >-
    Linux >= ae8f160e7eb24240a2a79fc4c815c6a0d4ee16cc <
    759dfc7d04bab1b0b86113f1164dc1fec192b859
  - Linux >= 5.4.296 < 5.4.297
  - Linux >= 5.10.240 < 5.10.241
  - Linux >= 5.15.189 < 5.15.190
  - Linux >= 6.1.146 < 6.1.149
  - Linux >= 6.6.99 < 6.6.103
  - Linux >= 6.12.39 < 6.12.43
  - Linux >= 6.15.7 < 6.15.11
  - Linux 6.16
published: '2025-09-04'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:42:01.494Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-38727'
references:
  - url: 'https://git.kernel.org/stable/c/47d49fd07f86d1f55ea1083287303d237e9e0922'
  - url: 'https://git.kernel.org/stable/c/6bee383ff83352a693d03efdf27cdd80742f71b2'
  - url: 'https://git.kernel.org/stable/c/f324959ad47e62e3cadaffa65d3cff790fb48529'
  - url: 'https://git.kernel.org/stable/c/d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e'
  - url: 'https://git.kernel.org/stable/c/346c820ef5135cf062fa3473da955ef8c5fb6929'
  - url: 'https://git.kernel.org/stable/c/44ddd7b1ae0b7edb2c832eb16798c827a05e58f0'
  - url: 'https://git.kernel.org/stable/c/78fcd69d55c5f11d7694c547eca767a1cfd38ec4'
  - url: 'https://git.kernel.org/stable/c/e8edc7de688791a337c068693f22e8d8b869df71'
  - url: 'https://git.kernel.org/stable/c/759dfc7d04bab1b0b86113f1164dc1fec192b859'
tags:
  - cve.org
epss: 0.00169
epssPercentile: 0.05487
ingestedAt: '2026-09-08T15:33:26.997Z'
---

## Overview

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

netlink: avoid infinite retry looping in netlink_unicast()

netlink_attachskb() checks for the socket's read memory allocation
constraints. Firstly, it has:

  rmem < READ_ONCE(sk->sk_rcvbuf)

to check if the just increased rmem value fits into the socket's receive
buffer. If not, it proceeds and tries to wait for the memory under:

  rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf)

The checks don't cover the case when skb->truesize + sk->sk_rmem_alloc is
equal to sk->sk_rcvbuf. Thus the function neither successfully accepts
these conditions, nor manages to reschedule the task - and is called in
retry loop for indefinite time which is caught as:

  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu:     0-....: (25999 ticks this GP) idle=ef2/1/0x4000000000000000 softirq=262269/262269 fqs=6212
  (t=26000 jiffies g=230833 q=259957)
  NMI backtrace for cpu 0
  CPU: 0 PID: 22 Comm: kauditd Not tainted 5.10.240 #68
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc42 04/01/2014
  Call Trace:
  <IRQ>
  dump_stack lib/dump_stack.c:120
  nmi_cpu_backtrace.cold lib/nmi_backtrace.c:105
  nmi_trigger_cpumask_backtrace lib/nmi_backtrace.c:62
  rcu_dump_cpu_stacks kernel/rcu/tree_stall.h:335
  rcu_sched_clock_irq.cold kernel/rcu/tree.c:2590
  update_process_times kernel/time/timer.c:1953
  tick_sched_handle kernel/time/tick-sched.c:227
  tick_sched_timer kernel/time/tick-sched.c:1399
  __hrtimer_run_queues kernel/time/hrtimer.c:1652
  hrtimer_interrupt kernel/time/hrtimer.c:1717
  __sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113
  asm_call_irq_on_stack arch/x86/entry/entry_64.S:808
  </IRQ>

  netlink_attachskb net/netlink/af_netlink.c:1234
  netlink_unicast net/netlink/af_netlink.c:1349
  kauditd_send_queue kernel/audit.c:776
  kauditd_thread kernel/audit.c:897
  kthread kernel/kthread.c:328
  ret_from_fork arch/x86/entry/entry_64.S:304

Restore the original behavior of the check which commit in Fixes
accidentally missed when restructuring the code.

Found by Linux Verification Center (linuxtesting.org).

## Affected

- `Linux >= 9da025150b7c14a8390fc06aea314c0a4011e82c < 47d49fd07f86d1f55ea1083287303d237e9e0922`
- `Linux >= c4ceaac5c5ba0b992ee1dc88e2a02421549e5c98 < 6bee383ff83352a693d03efdf27cdd80742f71b2`
- `Linux >= fd69af06101090eaa60b3d216ae715f9c0a58e5b < f324959ad47e62e3cadaffa65d3cff790fb48529`
- `Linux >= 76602d8e13864524382b0687dc32cd8f19164d5a < d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e`
- `Linux >= 55baecb9eb90238f60a8350660d6762046ebd3bd < 346c820ef5135cf062fa3473da955ef8c5fb6929`
- `Linux >= 4b8e18af7bea92f8b7fb92d40aeae729209db250 < 44ddd7b1ae0b7edb2c832eb16798c827a05e58f0`
- `Linux >= cd7ff61bfffd7000143c42bbffb85eeb792466d6 < 78fcd69d55c5f11d7694c547eca767a1cfd38ec4`
- `Linux >= ae8f160e7eb24240a2a79fc4c815c6a0d4ee16cc < e8edc7de688791a337c068693f22e8d8b869df71`
- `Linux >= ae8f160e7eb24240a2a79fc4c815c6a0d4ee16cc < 759dfc7d04bab1b0b86113f1164dc1fec192b859`
- `Linux >= 5.4.296 < 5.4.297`
- `Linux >= 5.10.240 < 5.10.241`
- `Linux >= 5.15.189 < 5.15.190`
- `Linux >= 6.1.146 < 6.1.149`
- `Linux >= 6.6.99 < 6.6.103`
- `Linux >= 6.12.39 < 6.12.43`
- `Linux >= 6.15.7 < 6.15.11`
- `Linux 6.16`

## Remediation

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