CVE-2025-37952: ksmbd: Fix UAF in __close_file_table_ids

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: 2025-05-20 · updated 2026-10-30
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix UAF in __close_file_table_ids A use-after-free is possible if one thread destroys the file via __ksmbd_close_fd while another thread holds a reference to it. The existing checks on fp->refcount are not sufficient to prevent this. The fix takes ft->lock around the section which removes the file from the file table. This prevents two threads acquiring the same file pointer via __close_file_table_ids, as well as the other functions which retrieve a file from the IDR and which already use this same lock.

Affected products

Linux kernel: from 5.15 before 6.6.91; from 6.7 before 6.12.29; from 6.13 before 6.14.7; 6.15-rc1, 6.15-rc2, 6.15-rc3, 6.15-rc4, 6.15-rc5 — fixed in 6.6.91, 6.12.29, 6.14.7
Linux: 5.15 — fixed in 6.15

How to fix

Upgrade to a fixed version: Linux kernel 6.6.91, 6.12.29, 6.14.7; Linux 6.15. Check the vendor advisory for mitigations.

References

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