Linux Kernel up to 6.16.1 netlink_unicast rmem allocation of resources

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4.9	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.16.1. It has been classified as critical. This impacts the function netlink_unicast. Performing a manipulation of the argument rmem results in allocation of resources. This vulnerability is identified as CVE-2025-38727. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.16.1. This affects the function netlink_unicast. The manipulation of the argument rmem with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. The summary by CVE is:

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).

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-38727 since 04/16/2025. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 261574 (Linux Distros Unpatched Vulnerability : CVE-2025-38727), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2 or 6.17-rc1 eliminates this vulnerability. Applying the patch 47d49fd07f86d1f55ea1083287303d237e9e0922/6bee383ff83352a693d03efdf27cdd80742f71b2/f324959ad47e62e3cadaffa65d3cff790fb48529/d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e/346c820ef5135cf062fa3473da955ef8c5fb6929/44ddd7b1ae0b7edb2c832eb16798c827a05e58f0/78fcd69d55c5f11d7694c547eca767a1cfd38ec4/e8edc7de688791a337c068693f22e8d8b869df71/759dfc7d04bab1b0b86113f1164dc1fec192b859 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (261574) and CERT Bund (WID-SEC-2025-1976). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Open Source Linux Kernel
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Microsoft Azure
• Dell Secure Connect Gateway
• IBM QRadar SIEM
• IBM Security Verify Access
• Dell NetWorker

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.296
• 5.10.240
• 5.15.189
• 6.1.148
• 6.6.102
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3
• 6.15.4
• 6.15.5
• 6.15.6
• 6.15.7
• 6.15.8
• 6.15.9
• 6.15.10
• 6.16.0
• 6.16.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 261574
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-38727

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.297/5.10.241/5.15.190/6.1.149/6.6.103/6.12.43/6.15.11/6.16.2/6.17-rc1
Patch: 47d49fd07f86d1f55ea1083287303d237e9e0922/6bee383ff83352a693d03efdf27cdd80742f71b2/f324959ad47e62e3cadaffa65d3cff790fb48529/d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e/346c820ef5135cf062fa3473da955ef8c5fb6929/44ddd7b1ae0b7edb2c832eb16798c827a05e58f0/78fcd69d55c5f11d7694c547eca767a1cfd38ec4/e8edc7de688791a337c068693f22e8d8b869df71/759dfc7d04bab1b0b86113f1164dc1fec192b859

Timelineinfo

04/16/2025 CVE reserved
09/04/2025 +141 days Advisory disclosed
09/04/2025 +0 days VulDB entry created
02/10/2026 +159 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38727 (🔒)
GCVE (CVE): GCVE-0-2025-38727
GCVE (VulDB): GCVE-100-322551
CERT Bund: WID-SEC-2025-1976 - Linux Kernel: Mehrere Schwachstellen erm&ouml;glichen Denial of Service

Entryinfo

Created: 09/04/2025 18:28
Updated: 02/10/2026 08:49
Changes: 09/04/2025 18:28 (59), 09/05/2025 20:45 (7), 09/07/2025 21:37 (2), 10/08/2025 20:23 (1), 12/10/2025 03:43 (1), 01/09/2026 06:57 (12), 01/15/2026 03:25 (1), 02/10/2026 08:49 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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