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From: Namjae Jeon <linkinjeon@kernel.org>
To: linux-cifs@vger.kernel.org
Cc: "Namjae Jeon" <linkinjeon@kernel.org>,
	"Tom Talpey" <tom@talpey.com>,
	"Ronnie Sahlberg" <ronniesahlberg@gmail.com>,
	"Ralph Böhme" <slow@samba.org>,
	"Steve French" <smfrench@gmail.com>,
	"Sergey Senozhatsky" <senozhatsky@chromium.org>,
	"Hyunchul Lee" <hyc.lee@gmail.com>
Subject: [PATCH v3 1/5] ksmbd: add the check to vaildate if stream protocol length exceeds maximum value
Date: Sun, 26 Sep 2021 22:55:39 +0900	[thread overview]
Message-ID: <20210926135543.119127-2-linkinjeon@kernel.org> (raw)
In-Reply-To: <20210926135543.119127-1-linkinjeon@kernel.org>

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>
Cc: Steve French <smfrench@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/connection.c | 10 ++++++----
 fs/ksmbd/smb_common.c |  6 ------
 fs/ksmbd/smb_common.h |  4 ++--
 3 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index af086d35398a..48b18b4ec117 100644
--- 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 1da67217698d..36fd9695fbc5 100644
--- 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;
@@ -267,11 +266,6 @@ 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 d7df19c97c4c..b8d225f7dbfc 100644
--- 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
@@ -492,8 +494,6 @@ 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,
-- 
2.25.1


  reply	other threads:[~2021-09-26 14:12 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-26 13:55 [PATCH v3 0/5] ksmbd: a bunch of patches Namjae Jeon
2021-09-26 13:55 ` Namjae Jeon [this message]
2021-09-26 13:55 ` [PATCH v3 2/5] ksmbd: add validation in smb2_ioctl Namjae Jeon
2021-09-26 13:55 ` [PATCH v3 3/5] ksmbd: add request buffer validation in smb2_set_info Namjae Jeon
2021-09-26 13:55 ` [PATCH v3 4/5] ksmbd: check strictly data area in ksmbd_smb2_check_message() Namjae Jeon
2021-09-26 13:55 ` [PATCH v3 5/5] ksmbd: add validation in smb2 negotiate Namjae Jeon
2021-09-26 14:27 ` [PATCH v3 0/5] ksmbd: a bunch of patches Ralph Boehme
2021-09-26 15:32   ` Namjae Jeon
2021-09-27 15:42 ` Ralph Boehme
2021-09-27 23:57   ` Namjae Jeon
2021-09-28  3:26     ` Ralph Boehme
2021-09-28 13:43       ` Ralph Boehme
2021-09-28 14:23         ` Namjae Jeon
2021-09-28 16:33           ` Ralph Boehme
2021-09-28 17:33             ` Jeremy Allison
2021-09-29 15:28               ` Tom Talpey
2021-09-29 15:42                 ` Jeremy Allison
2021-09-29 16:38                   ` Ralph Boehme
2021-09-29 16:45                     ` Tom Talpey
2021-09-29 17:08                       ` Ralph Boehme
2021-09-29 17:11                       ` Steve French
2021-09-29 17:18                         ` Ralph Boehme
2021-09-30  0:32                           ` Namjae Jeon
2021-09-30  0:51                             ` Hyunchul Lee
2021-09-30  7:57                             ` Ralph Boehme
2021-09-28 23:27           ` Namjae Jeon

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