In the Linux kernel, the following vulnerability has been resolved: xfs: add bounds checking to xlog_recover_process_data There is a lack of verification of the space occupied by fixed members of xlog_op_header in the xlog_recover_process_data. We can create a crafted image to trigger an out of bounds read by following these steps: 1) Mount an image of xfs, and do some file operations to leave records 2) Before umounting, copy the image for subsequent steps to simulate abnormal exit. Because umount will ensure that tail_blk and head_blk are the same, which will result in the inability to enter xlog_recover_process_data 3) Write a tool to parse and modify the copied image in step 2 4) Make the end of the xlog_op_header entries only 1 byte away from xlog_rec_header->h_size 5) xlog_rec_header->h_num_logops++ 6) Modify xlog_rec_header->h_crc Fix: Add a check to make sure there is sufficient space to access fixed members of xlog_op_header.
| 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 |
xfs: add bounds checking to xlog_recover_process_data