Linux Kernel up to 6.17-rc4 smc_ib_is_sg_need_sync null pointer dereference

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5.0	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.150/6.6.104/6.12.45/6.16.5/6.17-rc4. This vulnerability affects the function smc_ib_is_sg_need_sync. Performing a manipulation results in null pointer dereference. This vulnerability was named CVE-2025-39857. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.150/6.6.104/6.12.45/6.16.5/6.17-rc4. This affects the function smc_ib_is_sg_need_sync. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() BUG: kernel NULL pointer dereference, address: 00000000000002ec PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Workqueue: smc_hs_wq smc_listen_work [smc] RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc] ... Call Trace: <TASK> smcr_buf_map_link+0x211/0x2a0 [smc] __smc_buf_create+0x522/0x970 [smc] smc_buf_create+0x3a/0x110 [smc] smc_find_rdma_v2_device_serv+0x18f/0x240 [smc] ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc] smc_listen_find_device+0x1dd/0x2b0 [smc] smc_listen_work+0x30f/0x580 [smc] process_one_work+0x18c/0x340 worker_thread+0x242/0x360 kthread+0xe7/0x220 ret_from_fork+0x13a/0x160 ret_from_fork_asm+0x1a/0x30 </TASK> If the software RoCE device is used, ibdev->dma_device is a null pointer. As a result, the problem occurs. Null pointer detection is added to prevent problems.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-39857 since 04/16/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 265710 (Debian dsa-6008 : ata-modules-6.12.31-armmp-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.151, 6.6.105, 6.12.46, 6.16.6 or 6.17-rc5 eliminates this vulnerability. Applying the patch 0cdf1fd8fc59d44a48c694324611136910301ef9/f18d9b3abf9c6587372cc702f963a7592277ed56/eb929910bd4b4165920fa06a87b22cc6cae92e0e/34f17cbe027050b8d5316ea1b6f9bd7c378e92de/ba1e9421cf1a8369d25c3832439702a015d6b5f9 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 (265710) and CERT Bund (WID-SEC-2025-2099). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

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

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.150
• 6.6.104
• 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
• 6.12.43
• 6.12.44
• 6.12.45
• 6.16.0
• 6.16.1
• 6.16.2
• 6.16.3
• 6.16.4
• 6.16.5
• 6.17-rc1
• 6.17-rc2
• 6.17-rc3
• 6.17-rc4

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: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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: 265710
Nessus Name: Debian dsa-6008 : ata-modules-6.12.31-armmp-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.151/6.6.105/6.12.46/6.16.6/6.17-rc5
Patch: 0cdf1fd8fc59d44a48c694324611136910301ef9/f18d9b3abf9c6587372cc702f963a7592277ed56/eb929910bd4b4165920fa06a87b22cc6cae92e0e/34f17cbe027050b8d5316ea1b6f9bd7c378e92de/ba1e9421cf1a8369d25c3832439702a015d6b5f9

Timelineinfo

04/16/2025 CVE reserved
09/19/2025 +156 days Advisory disclosed
09/19/2025 +0 days VulDB entry created
01/20/2026 +123 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39857 (🔒)
GCVE (CVE): GCVE-0-2025-39857
GCVE (VulDB): GCVE-100-325053
CERT Bund: WID-SEC-2025-2099 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/19/2025 18:20
Updated: 01/20/2026 22:33
Changes: 09/19/2025 18:20 (58), 09/23/2025 18:31 (2), 10/20/2025 20:58 (7), 11/12/2025 05:12 (1), 11/29/2025 07:20 (1), 12/22/2025 10:56 (1), 01/20/2026 22:33 (12)
Complete: 🔍
Cache ID: 216::103

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Discussion

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