CVE-2025-37777: linux kernel Use-After-Free — Fix

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.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15 — 6.6.101
linux	linux_kernel	6.7 — 6.12.26
linux	linux_kernel	6.13 — 6.14.4
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

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

Frequently Asked Questions

What is CVE-2025-37777? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-37777? +

CVE-2025-37777 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-37777? +

CVE-2025-37777 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-37777? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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