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From: Ralph Boehme <slow@samba.org>
To: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>,
	Namjae Jeon <linkinjeon@kernel.org>, Tom Talpey <tom@talpey.com>,
	Ronnie Sahlberg <ronniesahlberg@gmail.com>,
	Steve French <smfrench@gmail.com>,
	Hyunchul Lee <hyc.lee@gmail.com>
Subject: [PATCH v7 3/9] ksmbd: add and use ksmbd_smb2_cur_pdu_buflen() in ksmbd_smb2_check_message()
Date: Tue,  5 Oct 2021 07:03:37 +0200	[thread overview]
Message-ID: <20211005050343.268514-4-slow@samba.org> (raw)
In-Reply-To: <20211005050343.268514-1-slow@samba.org>

No change in behaviour.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Ralph Boehme <slow@samba.org>
---
 fs/ksmbd/smb2misc.c | 36 +++++++++++++++++++++++++++---------
 fs/ksmbd/smb2pdu.h  |  1 +
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c
index 2cc031c39514..7ed266eb6c5e 100644
--- a/fs/ksmbd/smb2misc.c
+++ b/fs/ksmbd/smb2misc.c
@@ -333,14 +333,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
 	struct smb2_hdr *hdr = &pdu->hdr;
 	int command;
 	__u32 clc_len;  /* calculated length */
-	__u32 len = get_rfc1002_len(pdu);
-
-	if (le32_to_cpu(hdr->NextCommand) > 0) {
-		len = le32_to_cpu(hdr->NextCommand);
-	} else if (work->next_smb2_rcv_hdr_off) {
-		len -= work->next_smb2_rcv_hdr_off;
-		len = round_up(len, 8);
-	}
+	__u32 len = ksmbd_smb2_cur_pdu_buflen(work);
 
 	if (check_smb2_hdr(hdr))
 		return 1;
@@ -395,7 +388,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
 		 * Some windows servers (win2016) will pad also the final
 		 * PDU in a compound to 8 bytes.
 		 */
-		if (ALIGN(clc_len, 8) == len)
+		if (ALIGN(clc_len, 8) == ALIGN(len, 8))
 			return 0;
 
 		/*
@@ -427,3 +420,28 @@ int smb2_negotiate_request(struct ksmbd_work *work)
 {
 	return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE);
 }
+
+/**
+ * ksmbd_smb2_cur_pdu_buflen() - Get len of current SMB2 PDU buffer
+ * This returns the lenght including any possible padding.
+ * @work: smb work containing request buffer
+ */
+unsigned int ksmbd_smb2_cur_pdu_buflen(struct ksmbd_work *work)
+{
+	struct smb2_hdr *hdr = ksmbd_req_buf_next(work);
+	unsigned int buf_len;
+	unsigned int pdu_len;
+
+	if (hdr->NextCommand != 0) {
+		/*
+		 * hdr->NextCommand has already been validated by
+		 * init_chained_smb2_rsp().
+		 */
+		return __le32_to_cpu(hdr->NextCommand);
+	}
+
+	buf_len = get_rfc1002_len(work->request_buf);
+	pdu_len = buf_len - work->next_smb2_rcv_hdr_off;
+	return pdu_len;
+}
+
diff --git a/fs/ksmbd/smb2pdu.h b/fs/ksmbd/smb2pdu.h
index a6dec5ec6a54..c5fa8256b0bb 100644
--- a/fs/ksmbd/smb2pdu.h
+++ b/fs/ksmbd/smb2pdu.h
@@ -1680,6 +1680,7 @@ int smb2_set_rsp_credits(struct ksmbd_work *work);
 
 /* smb2 misc functions */
 int ksmbd_smb2_check_message(struct ksmbd_work *work);
+unsigned int ksmbd_smb2_cur_pdu_buflen(struct ksmbd_work *work);
 
 /* smb2 command handlers */
 int smb2_handle_negotiate(struct ksmbd_work *work);
-- 
2.31.1


  parent reply	other threads:[~2021-10-05  5:25 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-05  5:03 [PATCH v7 0/9] Buffer validation and compound handling patches Ralph Boehme
2021-10-05  5:03 ` [PATCH v7 1/9] ksmbd: use ksmbd_req_buf_next() in ksmbd_verify_smb_message() Ralph Boehme
2021-10-05  7:26   ` Namjae Jeon
2021-10-05  5:03 ` [PATCH v7 2/9] ksmbd: use ksmbd_req_buf_next() in ksmbd_smb2_check_message() Ralph Boehme
2021-10-05  7:27   ` Namjae Jeon
2021-10-05  5:03 ` Ralph Boehme [this message]
2021-10-05  7:29   ` [PATCH v7 3/9] ksmbd: add and use ksmbd_smb2_cur_pdu_buflen() " Namjae Jeon
2021-10-05  7:46     ` Ralph Boehme
2021-10-06 23:42       ` Namjae Jeon
2021-10-05  5:03 ` [PATCH v7 4/9] ksmbd: check buffer is big enough to access the SMB2 PUD body size field Ralph Boehme
2021-10-05  5:03 ` [PATCH v7 5/9] ksmdb: validate credit charge after validating SMB2 PDU body size Ralph Boehme
2021-10-05  7:58   ` Namjae Jeon
2021-10-05  5:03 ` [PATCH v7 6/9] ksmdb: use cmd helper variable in smb2_get_ksmbd_tcon() Ralph Boehme
2021-10-05  7:59   ` Namjae Jeon
2021-10-05  5:03 ` [PATCH v7 7/9] ksmdb: make smb2_get_ksmbd_tcon() callable with chained PDUs Ralph Boehme
2021-10-05  5:03 ` [PATCH v7 8/9] ksmbd: make smb2_check_user_session() callable for compound PDUs Ralph Boehme
2021-10-05  5:03 ` [PATCH v7 9/9] ksmdb: move session and tcon validation to __process_request() Ralph Boehme

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