[PATCH v2] ksmbd: fix partial normalized name responses

[Namjae Jeon <linkinjeon@kernel.org>]

Windows may request FILE_NORMALIZED_NAME_INFORMATION with an output
buffer that only fits the fixed portion of the variable-length response.
Treat the fixed portion as FILE_NORMALIZED_NAME_INFORMATION_SIZE so ksmbd
returns STATUS_BUFFER_OVERFLOW instead of STATUS_INFO_LENGTH_MISMATCH.

This avoids rejecting valid partial normalized-name responses.

Fixes: 6b8b79226bc3 ("ksmbd: fix partial file information responses")
Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/smb/server/smb2pdu.c | 3 +++
 fs/smb/server/smb2pdu.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 8acc5174530b..0436b7c898b1 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -7312,6 +7312,9 @@ static int smb2_get_info_file(struct ksmbd_work *work,
 		case FILE_ALTERNATE_NAME_INFORMATION:
 			fixed_len = FILE_ALTERNATE_NAME_INFORMATION_SIZE;
 			break;
+		case FILE_NORMALIZED_NAME_INFORMATION:
+			fixed_len = FILE_NORMALIZED_NAME_INFORMATION_SIZE;
+			break;
 		case FILE_STREAM_INFORMATION:
 			fixed_len = FILE_STREAM_INFORMATION_SIZE;
 			break;
diff --git a/fs/smb/server/smb2pdu.h b/fs/smb/server/smb2pdu.h
index a6200d8630e2..ca8e27f7b712 100644
--- a/fs/smb/server/smb2pdu.h
+++ b/fs/smb/server/smb2pdu.h
@@ -212,6 +212,7 @@ struct file_sparse {
 #define FILE_ALLOCATION_INFORMATION_SIZE      19
 #define FILE_END_OF_FILE_INFORMATION_SIZE     20
 #define FILE_ALTERNATE_NAME_INFORMATION_SIZE  8
+#define FILE_NORMALIZED_NAME_INFORMATION_SIZE 8
 #define FILE_STREAM_INFORMATION_SIZE          32
 #define FILE_PIPE_INFORMATION_SIZE            23
 #define FILE_PIPE_LOCAL_INFORMATION_SIZE      24
-- 
2.25.1