What’s Vulnerable › Vulnerabilities

CVE-2025-37777: ksmbd: fix use-after-free in __smb2_lease_break_noti()

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-05-01 · updated 2026-07-30
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __smb2_lease_break_noti() Move tcp_transport free to ksmbd_conn_free. If ksmbd connection is referenced when ksmbd server thread terminates, It will not be freed, but conn->tcp_transport is freed. __smb2_lease_break_noti can be performed asynchronously when the connection is disconnected. __smb2_lease_break_noti calls ksmbd_conn_write, which can cause use-after-free when conn->ksmbd_transport is already freed.

Affected products

• Linux kernel: from 5.15 before 6.6.101; from 6.7 before 6.12.26; from 6.13 before 6.14.4; 6.15-rc1, 6.15-rc2 — fixed in 6.12.26, 6.14.4, 6.6.101

How to fix

Upgrade to a fixed version: Linux kernel 6.12.26, 6.14.4, 6.6.101. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/1aec4d14cf81b7b3e7b69eb1cfa94144eed7138e
• https://git.kernel.org/stable/c/1da8bd9a10ecd718692732294d15fd801c0eabb5
• https://git.kernel.org/stable/c/21a4e47578d44c6b37c4fc4aba8ed7cc8dbb13de
• https://git.kernel.org/stable/c/e59796fc80603bcd8569d4d2e10b213c1918edb4

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