In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate owner of...
🔗 CVE IDs covered (1)
📋 Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate owner of durable handle on reconnect
Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID.
According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durable_owner structure to ksmbd_file to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner() to validate the identity of the requester during SMB2_CREATE (DHnC).
🔗 References (7)
- https://nvd.nist.gov/vuln/detail/CVE-2026-31717
- https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37
- https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8a
- https://git.kernel.org/stable/c/c908c853f304a4969b5aa10eba0b50350cc65b80
- https://git.kernel.org/stable/c/712cdf917e77a6444ce3836874829d770db20ee6
- https://git.kernel.org/stable/c/c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d
- https://github.com/advisories/GHSA-ffmp-v5q6-mvpq