[PATCH 1/2] ksmbd: downgrade ndr version error message to debug

[PATCH 1/2] ksmbd: downgrade ndr version error message to debug

[Namjae Jeon]

When user switch samba to ksmbd, The following message flood is coming
when accessing files. Samba seems to changs dos attribute version to v5.
This patch downgrade ndr version error message to debug.

$ dmesg
...
[68971.766914] ksmbd: v5 version is not supported
[68971.779808] ksmbd: v5 version is not supported
[68971.871544] ksmbd: v5 version is not supported
[68971.910135] ksmbd: v5 version is not supported
...

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/ndr.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/ksmbd/ndr.c b/fs/ksmbd/ndr.c
index 0ae8d08d85a8..4d9e0b54e3db 100644
--- a/fs/ksmbd/ndr.c
+++ b/fs/ksmbd/ndr.c
@@ -242,7 +242,7 @@ int ndr_decode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
 		return ret;
 
 	if (da->version != 3 && da->version != 4) {
-		pr_err("v%d version is not supported\n", da->version);
+		ksmbd_debug(VFS, "v%d version is not supported\n", da->version);
 		return -EINVAL;
 	}
 
@@ -251,7 +251,7 @@ int ndr_decode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
 		return ret;
 
 	if (da->version != version2) {
-		pr_err("ndr version mismatched(version: %d, version2: %d)\n",
+		ksmbd_debug(VFS, "ndr version mismatched(version: %d, version2: %d)\n",
 		       da->version, version2);
 		return -EINVAL;
 	}
@@ -457,7 +457,7 @@ int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
 	if (ret)
 		return ret;
 	if (acl->version != 4) {
-		pr_err("v%d version is not supported\n", acl->version);
+		ksmbd_debug(VFS, "v%d version is not supported\n", acl->version);
 		return -EINVAL;
 	}
 
@@ -465,7 +465,7 @@ int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
 	if (ret)
 		return ret;
 	if (acl->version != version2) {
-		pr_err("ndr version mismatched(version: %d, version2: %d)\n",
+		ksmbd_debug(VFS, "ndr version mismatched(version: %d, version2: %d)\n",
 		       acl->version, version2);
 		return -EINVAL;
 	}
-- 
2.25.1

[PATCH 2/2] ksmbd: limit pdu length size according to connection status

[Namjae Jeon]

Stream protocol length will never be larger than 16KB until session setup.
After session setup, the size of requests will not be larger than
16KB + SMB2 MAX WRITE size. This patch limits these invalidly oversized
requests and closes the connection immediately.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/connection.c | 17 +++++++++++++++--
 fs/ksmbd/smb2pdu.h    |  5 +++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index 5be203029bef..ee57db106c1e 100644
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -280,7 +280,7 @@ int ksmbd_conn_handler_loop(void *p)
 {
 	struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 	struct ksmbd_transport *t = conn->transport;
-	unsigned int pdu_size;
+	unsigned int pdu_size, max_allowed_pdu_size;
 	char hdr_buf[4] = {0,};
 	int size;
 
@@ -305,13 +305,26 @@ int ksmbd_conn_handler_loop(void *p)
 		pdu_size = get_rfc1002_len(hdr_buf);
 		ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 
+		if (conn->status == KSMBD_SESS_GOOD)
+			max_allowed_pdu_size =
+				SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
+		else
+			max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
+
+		if (pdu_size > max_allowed_pdu_size) {
+			pr_err_ratelimited("PDU length(%u) excceed maximum allowed pdu size(%u) on connection(%d)\n",
+					pdu_size, max_allowed_pdu_size,
+					conn->status);
+			break;
+		}
+
 		/*
 		 * Check if pdu size is valid (min : smb header size,
 		 * max : 0x00FFFFFF).
 		 */
 		if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 		    pdu_size > MAX_STREAM_PROT_LEN) {
-			continue;
+			break;
 		}
 
 		/* 4 for rfc1002 length field */
diff --git a/fs/ksmbd/smb2pdu.h b/fs/ksmbd/smb2pdu.h
index aa5dbe54f5a1..0c8a770fe318 100644
--- a/fs/ksmbd/smb2pdu.h
+++ b/fs/ksmbd/smb2pdu.h
@@ -24,8 +24,9 @@
 
 #define SMB21_DEFAULT_IOSIZE	(1024 * 1024)
 #define SMB3_DEFAULT_TRANS_SIZE	(1024 * 1024)
-#define SMB3_MIN_IOSIZE	(64 * 1024)
-#define SMB3_MAX_IOSIZE	(8 * 1024 * 1024)
+#define SMB3_MIN_IOSIZE		(64 * 1024)
+#define SMB3_MAX_IOSIZE		(8 * 1024 * 1024)
+#define SMB3_MAX_MSGSIZE	(4 * 4096)
 
 /*
  *	Definitions for SMB2 Protocol Data Units (network frames)
-- 
2.25.1