Linux Kernel up to 6.12.61/6.17.11/6.18.0 IOCTL comedi_fops.c get_valid_routes null pointer dereference

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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.12.61/6.17.11/6.18.0. The impacted element is the function get_valid_routes of the file drivers/comedi/comedi_fops.c of the component IOCTL Handler. Such manipulation leads to null pointer dereference. This vulnerability is traded as CVE-2025-68257. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.61/6.17.11/6.18.0 and classified as critical. Affected by this issue is the function get_valid_routes of the file drivers/comedi/comedi_fops.c of the component IOCTL Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to 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. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: comedi: check device's attached status in compat ioctls Syzbot identified an issue [1] that crashes kernel, seemingly due to unexistent callback dev->get_valid_routes(). By all means, this should not occur as said callback must always be set to get_zero_valid_routes() in __comedi_device_postconfig(). As the crash seems to appear exclusively in i386 kernels, at least, judging from [1] reports, the blame lies with compat versions of standard IOCTL handlers. Several of them are modified and do not use comedi_unlocked_ioctl(). While functionality of these ioctls essentially copy their original versions, they do not have required sanity check for device's attached status. This, in turn, leads to a possibility of calling select IOCTLs on a device that has not been properly setup, even via COMEDI_DEVCONFIG. Doing so on unconfigured devices means that several crucial steps are missed, for instance, specifying dev->get_valid_routes() callback. Fix this somewhat crudely by ensuring device's attached status before performing any ioctls, improving logic consistency between modern and compat functions. [1] Syzbot report: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... CR2: ffffffffffffffd6 CR3: 000000006c717000 CR4: 0000000000352ef0 Call Trace: <TASK> get_valid_routes drivers/comedi/comedi_fops.c:1322 [inline] parse_insn+0x78c/0x1970 drivers/comedi/comedi_fops.c:1401 do_insnlist_ioctl+0x272/0x700 drivers/comedi/comedi_fops.c:1594 compat_insnlist drivers/comedi/comedi_fops.c:3208 [inline] comedi_compat_ioctl+0x810/0x990 drivers/comedi/comedi_fops.c:3273 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] ...

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2025-68257 since 12/16/2025. The exploitation is known to be difficult. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 298404 (Debian dsa-6127 : affs-modules-6.1.0-37-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.62, 6.17.12, 6.18.1 or 6.19-rc1 eliminates this vulnerability. Applying the patch f6e629dfe6f590091c662a87c9fcf118b1c1c7dc/573b07d2e3d473ee7eb625ef87519922cf01168d/aac80e912de306815297a3b74f0426873ffa7dc3/0de7d9cd07a2671fa6089173bccc0b2afe6b93ee 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 (298404), EUVD (EUVD-2025-203740) and CERT Bund (WID-SEC-2025-2868). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.6

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

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298404
Nessus Name: Debian dsa-6127 : affs-modules-6.1.0-37-4kc-malta-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.62/6.17.12/6.18.1/6.19-rc1
Patch: f6e629dfe6f590091c662a87c9fcf118b1c1c7dc/573b07d2e3d473ee7eb625ef87519922cf01168d/aac80e912de306815297a3b74f0426873ffa7dc3/0de7d9cd07a2671fa6089173bccc0b2afe6b93ee

Timelineinfo

12/16/2025 Advisory disclosed
12/16/2025 +0 days CVE reserved
12/16/2025 +0 days VulDB entry created
02/22/2026 +68 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68257 (🔒)
GCVE (CVE): GCVE-0-2025-68257
GCVE (VulDB): GCVE-100-336794
EUVD: 🔒
CERT Bund: WID-SEC-2025-2868 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/16/2025 16:07
Updated: 02/22/2026 03:01
Changes: 12/16/2025 16:07 (60), 12/17/2025 11:04 (1), 01/12/2026 07:47 (1), 01/20/2026 04:28 (7), 02/04/2026 04:20 (1), 02/10/2026 09:45 (2), 02/22/2026 03:01 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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