Linux Kernel up to 6.18.5/6.19-rc4 idpf_vc_core_init null pointer dereference

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.5/6.19-rc4 and classified as critical. This impacts the function idpf_vc_core_init. Performing a manipulation results in null pointer dereference. This vulnerability is known as CVE-2026-23017. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.18.5/6.19-rc4. This affects the function idpf_vc_core_init. 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: idpf: fix error handling in the init_task on load If the init_task fails during a driver load, we end up without vports and netdevs, effectively failing the entire process. In that state a subsequent reset will result in a crash as the service task attempts to access uninitialized resources. Following trace is from an error in the init_task where the CREATE_VPORT (op 501) is rejected by the FW: [40922.763136] idpf 0000:83:00.0: Device HW Reset initiated [40924.449797] idpf 0000:83:00.0: Transaction failed (op 501) [40958.148190] idpf 0000:83:00.0: HW reset detected [40958.161202] BUG: kernel NULL pointer dereference, address: 00000000000000a8 ... [40958.168094] Workqueue: idpf-0000:83:00.0-vc_event idpf_vc_event_task [idpf] [40958.168865] RIP: 0010:idpf_vc_event_task+0x9b/0x350 [idpf] ... [40958.177932] Call Trace: [40958.178491] <TASK> [40958.179040] process_one_work+0x226/0x6d0 [40958.179609] worker_thread+0x19e/0x340 [40958.180158] ? __pfx_worker_thread+0x10/0x10 [40958.180702] kthread+0x10f/0x250 [40958.181238] ? __pfx_kthread+0x10/0x10 [40958.181774] ret_from_fork+0x251/0x2b0 [40958.182307] ? __pfx_kthread+0x10/0x10 [40958.182834] ret_from_fork_asm+0x1a/0x30 [40958.183370] </TASK> Fix the error handling in the init_task to make sure the service and mailbox tasks are disabled if the error happens during load. These are started in idpf_vc_core_init(), which spawns the init_task and has no way of knowing if it failed. If the error happens on reset, following successful driver load, the tasks can still run, as that will allow the netdevs to attempt recovery through another reset. Stop the PTP callbacks either way as those will be restarted by the call to idpf_vc_core_init() during a successful reset.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-23017 since 01/13/2026. 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 297487 (Linux Distros Unpatched Vulnerability : CVE-2026-23017), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.6 or 6.19-rc5 eliminates this vulnerability. Applying the patch a514c374edcd33581cdcccf8faa7cc606a600319/4d792219fe6f891b5b557a607ac8a0a14eda6e38 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 (297487), EUVD (EUVD-2026-5077) and CERT Bund (WID-SEC-2026-0280). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.19-rc1
• 6.19-rc2
• 6.19-rc3
• 6.19-rc4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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