Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: crash_dump: release keyring reference at the correct time restore_dm_crypt_keys_to_thread_keyring() gets a reference to the user keyring before restoring the saved dm-crypt keys. The same keyring reference is then passed to add_key_to_keyring() for each saved key, but add_key_to_keyring() drops that reference on every call. This is only balanced when exactly one key is restored. With multiple keys, the keyring reference is dropped too many times and may trigger a refcount underflow or use-after-free. When more than five keys are restored, a refcount underflow/use-after-free warning can be triggered. The early error paths after lookup_user_key() also return without dropping the keyring reference. Keep ownership of the keyring reference in restore_dm_crypt_keys_to_thread_keyring(), drop it once on all exit paths, and make add_key_to_keyring() only use the reference without consuming it.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 62f17d9df6924cf805de5ae970470615c1c8d9f2 before b0f7343a002f9c8b8378011f60482c76f3216dfd; affected 62f17d9df6924cf805de5ae970470615c1c8d9f2 before ed566979f99c5516cad45a76ae25e2a4928ffb67; affected 62f17d9df6924cf805de5ae970470615c1c8d9f2 before ada2e5a44e99113e08ad9b7b71396c6c572204da |
| Linux / Linux | affected 6.16; unaffected 0 before 6.16; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.