ksmbd: add the check to vaildate if stream protocol length exceeds maximum value

This patch add MAX_STREAM_PROT_LEN macro and check if stream protocol
length exceeds maximum value. opencode pdu size check in
ksmbd_pdu_size_has_room().

Cc: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Ralph Böhme <slow@samba.org>
Acked-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index af086d3..48b18b4 100644 (file)
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -296,10 +296,12 @@ int ksmbd_conn_handler_loop(void *p)
                pdu_size = get_rfc1002_len(hdr_buf);
                ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 
-               /* make sure we have enough to get to SMB header end */
-               if (!ksmbd_pdu_size_has_room(pdu_size)) {
-                       ksmbd_debug(CONN, "SMB request too short (%u bytes)\n",
-                                   pdu_size);
+               /*
+                * 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;
                }
 

diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c
index db8042a..b6c4c7e 100644 (file)
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -21,7 +21,6 @@ static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
 #define MAGIC_CHAR '~'
 #define PERIOD '.'
 #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
-#define KSMBD_MIN_SUPPORTED_HEADER_SIZE        (sizeof(struct smb2_hdr))
 
 struct smb_protocol {
        int             index;
@@ -294,11 +293,6 @@ int ksmbd_init_smb_server(struct ksmbd_work *work)
        return 0;
 }
 
-bool ksmbd_pdu_size_has_room(unsigned int pdu)
-{
-       return (pdu >= KSMBD_MIN_SUPPORTED_HEADER_SIZE - 4);
-}
-
 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
                                      struct ksmbd_file *dir,
                                      struct ksmbd_dir_info *d_info,

diff --git a/fs/ksmbd/smb_common.h b/fs/ksmbd/smb_common.h
index 994abed..6e79e75 100644 (file)
--- a/fs/ksmbd/smb_common.h
+++ b/fs/ksmbd/smb_common.h
@@ -48,6 +48,8 @@
 #define CIFS_DEFAULT_IOSIZE    (64 * 1024)
 #define MAX_CIFS_SMALL_BUFFER_SIZE 448 /* big enough for most */
 
+#define MAX_STREAM_PROT_LEN    0x00FFFFFF
+
 /* Responses when opening a file. */
 #define F_SUPERSEDED   0
 #define F_OPENED       1
@@ -493,8 +495,6 @@ int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count);
 
 int ksmbd_init_smb_server(struct ksmbd_work *work);
 
-bool ksmbd_pdu_size_has_room(unsigned int pdu);
-
 struct ksmbd_kstat;
 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work,
                                      int info_level,