In the Linux kernel, the following vulnerability has been resolved: usb: isp1760: Fix out-of-bounds array access Running the driver through kasan gives an interesting splat: BUG: KASAN: global-out-of-bounds in isp1760_register+0x180/0x70c Read of size 20 at addr f1db2e64 by task swapper/0/1 (...) isp1760_register from isp1760_plat_probe+0x1d8/0x220 (...) This happens because the loop reading the regmap fields for the different ISP1760 variants look like this: for (i = 0; i < HC_FIELD_MAX; i++) { ... } Meaning it expects the arrays to be at least HC_FIELD_MAX - 1 long. However the arrays isp1760_hc_reg_fields[], isp1763_hc_reg_fields[], isp1763_hc_volatile_ranges[] and isp1763_dc_volatile_ranges[] are dynamically sized during compilation. Fix this by putting an empty assignment to the [HC_FIELD_MAX] and [DC_FIELD_MAX] array member at the end of each array. This will make the array one member longer than it needs to be, but avoids the risk of overwriting whatever is inside [HC_FIELD_MAX - 1] and is simple and intuitive to read. Also add comments explaining what is going on.
| 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
|
High (H)
|
Divulgation totale 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 |
usb: isp1760: Fix out-of-bounds array access