Linux Kernel up to 6.19-rc3 smc91x.c smc_special_trylock privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.3/6.19-rc3. Impacted is the function smc_special_trylock of the file smc91x.c. Executing a manipulation can lead to an unknown weakness. The identification of this vulnerability is CVE-2025-71132. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.3/6.19-rc3 and classified as critical. This vulnerability affects the function smc_special_trylock of the file smc91x.c. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: smc91x: fix broken irq-context in PREEMPT_RT When smc91x.c is built with PREEMPT_RT, the following splat occurs in FVP_RevC: [ 13.055000] smc91x LNRO0003:00 eth0: link up, 10Mbps, half-duplex, lpa 0x0000 [ 13.062137] BUG: workqueue leaked atomic, lock or RCU: kworker/2:1[106] [ 13.062137] preempt=0x00000000 lock=0->0 RCU=0->1 workfn=mld_ifc_work [ 13.062266] C ** replaying previous printk message ** [ 13.062266] CPU: 2 UID: 0 PID: 106 Comm: kworker/2:1 Not tainted 6.18.0-dirty #179 PREEMPT_{RT,(full)} [ 13.062353] Hardware name: , BIOS [ 13.062382] Workqueue: mld mld_ifc_work [ 13.062469] Call trace: [ 13.062494] show_stack+0x24/0x40 (C) [ 13.062602] __dump_stack+0x28/0x48 [ 13.062710] dump_stack_lvl+0x7c/0xb0 [ 13.062818] dump_stack+0x18/0x34 [ 13.062926] process_scheduled_works+0x294/0x450 [ 13.063043] worker_thread+0x260/0x3d8 [ 13.063124] kthread+0x1c4/0x228 [ 13.063235] ret_from_fork+0x10/0x20 This happens because smc_special_trylock() disables IRQs even on PREEMPT_RT, but smc_special_unlock() does not restore IRQs on PREEMPT_RT. The reason is that smc_special_unlock() calls spin_unlock_irqrestore(), and rcu_read_unlock_bh() in __dev_queue_xmit() cannot invoke rcu_read_unlock() through __local_bh_enable_ip() when current->softirq_disable_cnt becomes zero. To address this issue, replace smc_special_trylock() with spin_trylock_irqsave().

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2025-71132 since 01/13/2026. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/25/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298659 (Debian dla-4476 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.160, 6.6.120, 6.12.64, 6.18.4 or 6.19-rc4 eliminates this vulnerability. Applying the patch 9d222141b00156509d67d80c771fbefa92c43ace/ef277ae121b3249c99994652210a326b52d527b0/36561b86cb2501647662cfaf91286dd6973804a6/b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3/6402078bd9d1ed46e79465e1faaa42e3458f8a33 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 (298659), EUVD (EUVD-2026-2483) and CERT Bund (WID-SEC-2026-0119). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Open Source Linux Kernel

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298659
Nessus Name: Debian dla-4476 : linux-config-6.1 - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.160/6.6.120/6.12.64/6.18.4/6.19-rc4
Patch: 9d222141b00156509d67d80c771fbefa92c43ace/ef277ae121b3249c99994652210a326b52d527b0/36561b86cb2501647662cfaf91286dd6973804a6/b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3/6402078bd9d1ed46e79465e1faaa42e3458f8a33

Timelineinfo

01/13/2026 CVE reserved
01/14/2026 +1 days Advisory disclosed
01/14/2026 +0 days VulDB entry created
03/25/2026 +70 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-71132 (🔒)
GCVE (CVE): GCVE-0-2025-71132
GCVE (VulDB): GCVE-100-341104
EUVD: 🔒
CERT Bund: WID-SEC-2026-0119 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/14/2026 17:54
Updated: 03/25/2026 23:19
Changes: 01/14/2026 17:54 (58), 01/16/2026 07:08 (7), 01/20/2026 10:53 (1), 02/16/2026 14:08 (2), 03/25/2026 23:19 (10)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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