ksmbd: free ppace array on error in parse_dacl

The ppace array is not freed if one of the init_acl_state() calls inside
parse_dacl() fails. At the moment the function may fail only due to the
memory allocation errors so it's highly unlikely in this case but
nevertheless a fix is needed.

Move ppace allocation after the init_acl_state() calls with proper error
handling.

Found by Linux Verification Center (linuxtesting.org).

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: [email protected]
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>

smbacl.c

@@ -459,10 +459,6 @@ static void parse_dacl(struct user_namespace *user_ns,
 	if (num_aces > ULONG_MAX / sizeof(struct smb_ace *))
 		return;
 
-	ppace = kmalloc_array(num_aces, sizeof(struct smb_ace *), GFP_KERNEL);
-	if (!ppace)
-		return;
-
 	ret = init_acl_state(&acl_state, num_aces);
 	if (ret)
 		return;
@@ -472,6 +468,13 @@ static void parse_dacl(struct user_namespace *user_ns,
 		return;
 	}
 
+	ppace = kmalloc_array(num_aces, sizeof(struct smb_ace *), GFP_KERNEL);
+	if (!ppace) {
+		free_acl_state(&default_acl_state);
+		free_acl_state(&acl_state);
+		return;
+	}
+
 	/*
 	 * reset rwx permissions for user/group/other.
 	 * Also, if num_aces is 0 i.e. DACL has no ACEs,