Linux Kernel ksmbd smb2_tree_connect tree_conns resource consumption

Summaryinfo

A vulnerability was found in Linux Kernel. It has been declared as critical. This affects the function smb2_tree_connect of the component ksmbd. Such manipulation of the argument tree_conns leads to resource consumption. This vulnerability is uniquely identified as CVE-2026-98162. The attack can be launched remotely. No exploit exists. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in Linux Kernel (version now known). It has been rated as critical. Affected by this issue is the function smb2_tree_connect of the component ksmbd. The manipulation of the argument tree_conns with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix tree connection leak in smb2_tree_connect() See the procedure below: smb2_tree_connect ksmbd_tree_conn_connect xa_store(&sess->tree_conns, tree_conn->id, tree_conn) ksmbd_counter_inc(KSMBD_COUNTER_TREE_CONNS) ksmbd_share_tree_conn_inc(sc) ksmbd_iov_pin_rsp // fail status.ret = KSMBD_TREE_CONN_STATUS_NOMEM // do not disconnect tree_conn Disconnect the new tree connection if ksmbd_iov_pin_rsp() fails.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-98162 since 09/25/2026. The exploitation is known to be easy. The attack may be launched remotely. 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 09/25/2026). The MITRE ATT&CK project declares the attack technique as T1499.

Applying the patch a6c88e5e3a75f1e4a98ad4bc4037465ccd7925bc/39f2032096715daae5f6fd0f587ca7a474b019df is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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