[PATCH 4.20 128/145] smb3: fix large reads on encrypted connections

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paul Aurich <paul@xxxxxxxxxxxxxx>

commit 6d2f84eee098540ae857998fe32f29b9e2cd9613 upstream.

When passing a large read to receive_encrypted_read(), ensure that the
demultiplex_thread knows that a MID was processed.  Without this, those
operations never complete.

This is a similar issue/fix to lease break handling:
commit 7af929d6d05ba5564139718e30d5bc96bdbc716a
("smb3: fix lease break problem introduced by compounding")

CC: Stable <stable@xxxxxxxxxxxxxxx> # 4.19+
Fixes: b24df3e30cbf ("cifs: update receive_encrypted_standard to handle compounded responses")
Signed-off-by: Paul Aurich <paul@xxxxxxxxxxxxxx>
Tested-by: Yves-Alexis Perez <corsac@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/cifs/smb2ops.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3384,8 +3384,10 @@ smb3_receive_transform(struct TCP_Server
 	}
 
 	/* TODO: add support for compounds containing READ. */
-	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server))
+	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server)) {
+		*num_mids = 1;
 		return receive_encrypted_read(server, &mids[0]);
+	}
 
 	return receive_encrypted_standard(server, mids, bufs, num_mids);
 }