From: ChenXiaoSong <chenxiaosong@kylinos.cn>
Date: Sat, 20 Dec 2025 13:25:50 +0000 (+0800)
Subject: smb/server: fix minimum SMB1 PDU size
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3b9c30eb8f5aaad4a54cdfa470b74c0467cc71e8;p=thirdparty%2Flinux.git

smb/server: fix minimum SMB1 PDU size

Since the RFC1002 header has been removed from `struct smb_hdr`,
the minimum SMB1 PDU size should be updated as well.

Fixes: 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr")
Suggested-by: David Howells <dhowells@redhat.com>
Suggested-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c
index b2afd8a43b0a..487b5562c771 100644
--- a/fs/smb/server/connection.c
+++ b/fs/smb/server/connection.c
@@ -295,7 +295,8 @@ bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 	return true;
 }
 
-#define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
+/* "+2" for BCC field (ByteCount, 2 bytes) */
+#define SMB1_MIN_SUPPORTED_PDU_SIZE (sizeof(struct smb_hdr) + 2)
 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
 
 /**
@@ -363,7 +364,7 @@ recheck:
 		if (pdu_size > MAX_STREAM_PROT_LEN)
 			break;
 
-		if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
+		if (pdu_size < SMB1_MIN_SUPPORTED_PDU_SIZE)
 			break;
 
 		/* 4 for rfc1002 length field */