smb/server: fix potential null-ptr-deref of lease_ctx_info in smb2_open()

[ Upstream commit 4e8771a3666c8f216eefd6bd2fd50121c6c437db ]

null-ptr-deref will occur when (req_op_level == SMB2_OPLOCK_LEVEL_LEASE)
and parse_lease_state() return NULL.

Fix this by check if 'lease_ctx_info' is NULL.

Additionally, remove the redundant parentheses in
parse_durable_handle_context().

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c
index a8f52c4ebbdadd2c966b5a247058c3205be6e0f3..e546ffa57b55ab8ae646731f5a76621a7bb29768 100644 (file)
--- a/fs/smb/server/oplock.c
+++ b/fs/smb/server/oplock.c
@@ -1510,7 +1510,7 @@ void create_lease_buf(u8 *rbuf, struct lease *lease)
  * parse_lease_state() - parse lease context containted in file open request
  * @open_req:  buffer containing smb2 file open(create) request
  *
- * Return:  oplock state, -ENOENT if create lease context not found
+ * Return: allocated lease context object on success, otherwise NULL
  */
 struct lease_ctx_info *parse_lease_state(void *open_req)
 {

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index c55924f5164e20eddec08c463bb6e7ea9ffa2847..458cc736286aaedee54d3a7a41407df5e41e06bc 100644 (file)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -2771,8 +2771,8 @@ static int parse_durable_handle_context(struct ksmbd_work *work,
                                }
                        }
 
-                       if (((lc && (lc->req_state & SMB2_LEASE_HANDLE_CACHING_LE)) ||
-                            req_op_level == SMB2_OPLOCK_LEVEL_BATCH)) {
+                       if ((lc && (lc->req_state & SMB2_LEASE_HANDLE_CACHING_LE)) ||
+                           req_op_level == SMB2_OPLOCK_LEVEL_BATCH) {
                                dh_info->CreateGuid =
                                        durable_v2_blob->CreateGuid;
                                dh_info->persistent =
@@ -2792,8 +2792,8 @@ static int parse_durable_handle_context(struct ksmbd_work *work,
                                goto out;
                        }
 
-                       if (((lc && (lc->req_state & SMB2_LEASE_HANDLE_CACHING_LE)) ||
-                            req_op_level == SMB2_OPLOCK_LEVEL_BATCH)) {
+                       if ((lc && (lc->req_state & SMB2_LEASE_HANDLE_CACHING_LE)) ||
+                           req_op_level == SMB2_OPLOCK_LEVEL_BATCH) {
                                ksmbd_debug(SMB, "Request for durable open\n");
                                dh_info->type = dh_idx;
                        }
@@ -3415,7 +3415,7 @@ int smb2_open(struct ksmbd_work *work)
                        goto err_out1;
                }
        } else {
-               if (req_op_level == SMB2_OPLOCK_LEVEL_LEASE) {
+               if (req_op_level == SMB2_OPLOCK_LEVEL_LEASE && lc) {
                        if (S_ISDIR(file_inode(filp)->i_mode)) {
                                lc->req_state &= ~SMB2_LEASE_WRITE_CACHING_LE;
                                lc->is_dir = true;