CVE-2026-90152: smb/server: fix session leak in ksmbd_session_register()

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix session leak in ksmbd_session_register() See the procedure below: smb2_sess_setup ksmbd_smb2_session_create __session_create atomic_set(&sess->refcnt, 2) hash_add(sessions_table, &sess->hlist, sess->id) ksmbd_session_register xa_store(&conn->sessions, sess->id, sess) // fail ksmbd_user_session_put atomic_dec(&sess->refcnt) // refcnt is 1, session is not freed Remove the session from sessions_table and drop its table reference if xa_store() fails.

Affected products

Linux: from 6.1.29 before 6.1.191; from 5.15.145 before 5.16; from 6.2.16 before 6.3; from 6.3.2 before 6.4 — fixed in 6.1.191, 5.16, 6.3, 6.4

How to fix

Upgrade to a fixed version: Linux 6.1.191, 5.16, 6.3, 6.4. Check the vendor advisory for mitigations.

References

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