[ Upstream commit d592a9158a112d419f341f035d18d02f8d232def ]
When file is changed using notepad on read-only share(read_only = yes in ksmbd.conf), There is a problem where existing data is truncated. notepad in windows try to O_TRUNC open(FILE_OVERWRITE_IF) and all data in file is truncated. This patch don't allow O_TRUNC open on read-only share and add KSMBD_TREE_CONN_FLAG_WRITABLE check in smb2_set_info().
Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com --- fs/ksmbd/smb2pdu.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 5975a2bc471f..4d6663ab3d03 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2969,7 +2969,7 @@ int smb2_open(struct ksmbd_work *work) &may_flags);
if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) { - if (open_flags & O_CREAT) { + if (open_flags & (O_CREAT | O_TRUNC)) { ksmbd_debug(SMB, "User does not have write permission\n"); rc = -EACCES; @@ -5946,12 +5946,6 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp, } case FILE_RENAME_INFORMATION: { - if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) { - ksmbd_debug(SMB, - "User does not have write permission\n"); - return -EACCES; - } - if (buf_len < sizeof(struct smb2_file_rename_info)) return -EINVAL;
@@ -5971,12 +5965,6 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp, } case FILE_DISPOSITION_INFORMATION: { - if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) { - ksmbd_debug(SMB, - "User does not have write permission\n"); - return -EACCES; - } - if (buf_len < sizeof(struct smb2_file_disposition_info)) return -EINVAL;
@@ -6038,7 +6026,7 @@ int smb2_set_info(struct ksmbd_work *work) { struct smb2_set_info_req *req; struct smb2_set_info_rsp *rsp; - struct ksmbd_file *fp; + struct ksmbd_file *fp = NULL; int rc = 0; unsigned int id = KSMBD_NO_FID, pid = KSMBD_NO_FID;
@@ -6058,6 +6046,13 @@ int smb2_set_info(struct ksmbd_work *work) rsp = smb2_get_msg(work->response_buf); }
+ if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) { + ksmbd_debug(SMB, "User does not have write permission\n"); + pr_err("User does not have write permission\n"); + rc = -EACCES; + goto err_out; + } + if (!has_file_id(id)) { id = req->VolatileFileId; pid = req->PersistentFileId;