[PATCH AUTOSEL 5.15 11/33] ksmbd: don't align last entry offset in smb2 query directory

[Sasha Levin]

From: Namjae Jeon <linkinjeon@xxxxxxxxxx>

[ Upstream commit 04e260948a160d3b7d622bf4c8a96fa4577c09bd ]

When checking smb2 query directory packets from other servers,
OutputBufferLength is different with ksmbd. Other servers add an unaligned
next offset to OutputBufferLength for the last entry.

Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ksmbd/smb2pdu.c | 7 ++++---
 fs/ksmbd/vfs.h     | 1 +
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 70685cbbec8c0..192d8308afc27 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -3422,9 +3422,9 @@ static int smb2_populate_readdir_entry(struct ksmbd_conn *conn, int info_level,
 		goto free_conv_name;
 	}
 
-	struct_sz = readdir_info_level_struct_sz(info_level);
-	next_entry_offset = ALIGN(struct_sz - 1 + conv_len,
-				  KSMBD_DIR_INFO_ALIGNMENT);
+	struct_sz = readdir_info_level_struct_sz(info_level) - 1 + conv_len;
+	next_entry_offset = ALIGN(struct_sz, KSMBD_DIR_INFO_ALIGNMENT);
+	d_info->last_entry_off_align = next_entry_offset - struct_sz;
 
 	if (next_entry_offset > d_info->out_buf_len) {
 		d_info->out_buf_len = 0;
@@ -3976,6 +3976,7 @@ int smb2_query_dir(struct ksmbd_work *work)
 		((struct file_directory_info *)
 		((char *)rsp->Buffer + d_info.last_entry_offset))
 		->NextEntryOffset = 0;
+		d_info.data_count -= d_info.last_entry_off_align;
 
 		rsp->StructureSize = cpu_to_le16(9);
 		rsp->OutputBufferOffset = cpu_to_le16(72);
diff --git a/fs/ksmbd/vfs.h b/fs/ksmbd/vfs.h
index b0d5b8feb4a36..432c947731779 100644
--- a/fs/ksmbd/vfs.h
+++ b/fs/ksmbd/vfs.h
@@ -86,6 +86,7 @@ struct ksmbd_dir_info {
 	int		last_entry_offset;
 	bool		hide_dot_file;
 	int		flags;
+	int		last_entry_off_align;
 };
 
 struct ksmbd_readdir_data {
-- 
2.34.1