ksmbd: fix passing freed memory 'aux_payload_buf'

[ Upstream commit 59d8d24f4610333560cf2e8fe3f44cafe30322eb ]

The patch e2b76ab8b5c9: "ksmbd: add support for read compound" leads
to the following Smatch static checker warning:

  fs/smb/server/smb2pdu.c:6329 smb2_read()
        warn: passing freed memory 'aux_payload_buf'

It doesn't matter that we're passing a freed variable because nbytes is
zero. This patch set "aux_payload_buf = NULL" to make smatch silence.

Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 27ebb103a19c8bf59c304cf54d19c83b137f3bde..e82aac933e45cebb0948c41c0e33ae1e1af83513 100644 (file)
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -6314,7 +6314,7 @@ int smb2_read(struct ksmbd_work *work)
                                                      aux_payload_buf,
                                                      nbytes);
                kvfree(aux_payload_buf);
-
+               aux_payload_buf = NULL;
                nbytes = 0;
                if (remain_bytes < 0) {
                        err = (int)remain_bytes;