In the Linux kernel, the following vulnerability has been resolved: tracing: Have process_string() also allow arrays In order to catch a common bug where a TRACE_EVENT() TP_fast_assign() assigns an address of an allocated string to the ring buffer and then references it in TP_printk(), which can be executed hours later when the string is free, the function test_event_printk() runs on all events as they are registered to make sure there's no unwanted dereferencing. It calls process_string() to handle cases in TP_printk() format that has "%s". It returns whether or not the string is safe. But it can have some false positives. For instance, xe_bo_move() has: TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s", __entry->move_lacks_source ? "yes" : "no", __entry->bo, __entry->size, xe_mem_type_to_name[__entry->old_placement], xe_mem_type_to_name[__entry->new_placement], __get_str(device_id)) Where the "%s" references into xe_mem_type_to_name[]. This is an array of pointers that should be safe for the event to access. Instead of flagging this as a bad reference, if a reference points to an array, where the record field is the index, consider it safe.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
Low (L)
|
Authentifié avec compte utilisateur basique |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
tracing: Have process_string() also allow arrays