In the Linux kernel, the following vulnerability has been resolved: smb: Fix regression in writes when non-standard maximum write size negotiated The conversion to netfs in the 6.3 kernel caused a regression when maximum write size is set by the server to an unexpected value which is not a multiple of 4096 (similarly if the user overrides the maximum write size by setting mount parm "wsize", but sets it to a value that is not a multiple of 4096). When negotiated write size is not a multiple of 4096 the netfs code can skip the end of the final page when doing large sequential writes, causing data corruption. This section of code is being rewritten/removed due to a large netfs change, but until that point (ie for the 6.3 kernel until now) we can not support non-standard maximum write sizes. Add a warning if a user specifies a wsize on mount that is not a multiple of 4096 (and round down), also add a change where we round down the maximum write size if the server negotiates a value that is not a multiple of 4096 (we also have to check to make sure that we do not round it down to zero).
| Métrique | Valeur | Interprétation |
|---|---|---|
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AV (Vecteur d'Attaque)
Attack Vector
|
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 |
|
PR (Privilèges Requis)
Privileges Required
|
Low (L)
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Authentifié avec compte utilisateur basique |
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UI (Interaction Utilisateur)
User Interaction
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None (N)
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Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
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Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
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C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
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None (N)
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Aucune modification de données possible |
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A (Impact Disponibilité)
Availability Impact
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High (H)
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Interruption totale du service possible |
smb: Fix regression in writes when non-standard maximum write size negotiated