In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free of signing key Customers have reported use-after-free in @ses->auth_key.response with SMB2.1 + sign mounts which occurs due to following race: task A task B cifs_mount() dfs_mount_share() get_session() cifs_mount_get_session() cifs_send_recv() cifs_get_smb_ses() compound_send_recv() cifs_setup_session() smb2_setup_request() kfree_sensitive() smb2_calc_signature() crypto_shash_setkey() *UAF* Fix this by ensuring that we have a valid @ses->auth_key.response by checking whether @ses->ses_status is SES_GOOD or SES_EXITING with @ses->ses_lock held. After commit 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()"), we made sure to call ->logoff() only when @ses was known to be good (e.g. valid ->auth_key.response), so it's safe to access signing key when @ses->ses_status == SES_EXITING.
| Métrique | Valeur | Interprétation |
|---|---|---|
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AV (Vecteur d'Attaque)
Attack Vector
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Local (L)
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Exploit nécessite un accès local au système |
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AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
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PR (Privilèges Requis)
Privileges Required
|
Low (L)
|
Authentifié avec compte utilisateur basique |
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UI (Interaction Utilisateur)
User Interaction
|
None (N)
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Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
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C (Impact Confidentialité)
Confidentiality Impact
|
High (H)
|
Divulgation totale d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
High (H)
|
Modification totale des données possible |
|
A (Impact Disponibilité)
Availability Impact
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High (H)
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Interruption totale du service possible |
smb: client: fix use-after-free of signing key