[PATCH v7 3/9] ksmbd: add and use ksmbd_smb2_cur_pdu_buflen() in ksmbd_smb2_check_message()

Ralph Boehme
2021-10-05T05:25:25Z

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