In the Linux kernel, the following vulnerability has been resolved: ocfs2: uncache inode which has failed entering the group Syzbot has reported the following BUG: kernel BUG at fs/ocfs2/uptodate.c:509! ... Call Trace: <TASK> ? __die_body+0x5f/0xb0 ? die+0x9e/0xc0 ? do_trap+0x15a/0x3a0 ? ocfs2_set_new_buffer_uptodate+0x145/0x160 ? do_error_trap+0x1dc/0x2c0 ? ocfs2_set_new_buffer_uptodate+0x145/0x160 ? __pfx_do_error_trap+0x10/0x10 ? handle_invalid_op+0x34/0x40 ? ocfs2_set_new_buffer_uptodate+0x145/0x160 ? exc_invalid_op+0x38/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? ocfs2_set_new_buffer_uptodate+0x2e/0x160 ? ocfs2_set_new_buffer_uptodate+0x144/0x160 ? ocfs2_set_new_buffer_uptodate+0x145/0x160 ocfs2_group_add+0x39f/0x15a0 ? __pfx_ocfs2_group_add+0x10/0x10 ? __pfx_lock_acquire+0x10/0x10 ? mnt_get_write_access+0x68/0x2b0 ? __pfx_lock_release+0x10/0x10 ? rcu_read_lock_any_held+0xb7/0x160 ? __pfx_rcu_read_lock_any_held+0x10/0x10 ? smack_log+0x123/0x540 ? mnt_get_write_access+0x68/0x2b0 ? mnt_get_write_access+0x68/0x2b0 ? mnt_get_write_access+0x226/0x2b0 ocfs2_ioctl+0x65e/0x7d0 ? __pfx_ocfs2_ioctl+0x10/0x10 ? smack_file_ioctl+0x29e/0x3a0 ? __pfx_smack_file_ioctl+0x10/0x10 ? lockdep_hardirqs_on_prepare+0x43d/0x780 ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10 ? __pfx_ocfs2_ioctl+0x10/0x10 __se_sys_ioctl+0xfb/0x170 do_syscall_64+0xf3/0x230 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... </TASK> When 'ioctl(OCFS2_IOC_GROUP_ADD, ...)' has failed for the particular inode in 'ocfs2_verify_group_and_input()', corresponding buffer head remains cached and subsequent call to the same 'ioctl()' for the same inode issues the BUG() in 'ocfs2_set_new_buffer_uptodate()' (trying to cache the same buffer head of that inode). Fix this by uncaching the buffer head with 'ocfs2_remove_from_cache()' on error path in 'ocfs2_group_add()'.
| 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 |
ocfs2: uncache inode which has failed entering the group