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ksmbd: validate credit charge after validating SMB2 PDU body size

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smb2_validate_credit_charge() accesses fields in the SMB2 PDU body,
but until smb2_calc_size() is called the PDU has not yet been verified
to be large enough to access the PDU dynamic part length field.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Ralph Boehme 2021-10-15 12:52:58 +09:00 committed by Steve French
parent 2ea086e35c
commit 7a33488705
1 changed files with 10 additions and 9 deletions
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19
fs/ksmbd/smb2misc.c
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@ -400,26 +400,20 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
}
}
if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
smb2_validate_credit_charge(work->conn, hdr)) {
work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
return 1;
}
if (smb2_calc_size(hdr, &clc_len))
return 1;
if (len != clc_len) {
/* client can return one byte more due to implied bcc[0] */
if (clc_len == len + 1)
return 0;
goto validate_credit;
/*
* Some windows servers (win2016) will pad also the final
* PDU in a compound to 8 bytes.
*/
if (ALIGN(clc_len, 8) == len)
return 0;
goto validate_credit;
/*
* windows client also pad up to 8 bytes when compounding.
@ -432,7 +426,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
"cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
len, clc_len, command,
le64_to_cpu(hdr->MessageId));
return 0;
goto validate_credit;
}
ksmbd_debug(SMB,
@ -443,6 +437,13 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
return 1;
}
validate_credit:
if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
smb2_validate_credit_charge(work->conn, hdr)) {
work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
return 1;
}
return 0;
}