Linux Kernel up to 7.2.5 ksmbd ksmbd_server_init allocation of resources

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 7.2.5. Impacted is the function ksmbd_server_init of the component ksmbd. The manipulation results in allocation of resources. This vulnerability is identified as CVE-2026-90164. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 7.2.5. Affected is the function ksmbd_server_init of the component ksmbd. The manipulation 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. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: smb/server: abort initialization when proc setup fails ksmbd_server_init() calls ksmbd_proc_init() before creating the remaining proc entries and server subsystems. ksmbd_proc_init() tears down partial state on a procfs or percpu_counter allocation failure, but returns void, so ksmbd_server_init() continues as if the counters were usable. Once userspace starts the server, server_ctrl_handle_init() calls ksmbd_proc_reset(), which reaches percpu_counter_set() with a NULL per-CPU counters pointer on SMP systems. The later ksmbd_proc_create() calls also receive a NULL parent and may create entries in the /proc root; ksmbd_proc_cleanup() cannot remove those entries because ksmbd_proc_fs is NULL.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-90164 since 09/11/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/17/2026). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch fb4ba2bdfc1de8866e7c8e00df99f4b03ff42f09/db97f3763727d652112ae70038d4e17b3ce277bb is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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