cifs: check if SMB2 PDU size has been padded and suppress the warning
[ Upstream commit e6c47dd0da1e3a484e778046fc10da0b20606a86 ]
Some SMB2/3 servers, Win2016 but possibly others too, adds padding
not only between PDUs in a compound but also to the final PDU.
This padding extends the PDU to a multiple of 8 bytes.
Check if the unexpected length looks like this might be the case
and avoid triggering the log messages for :
"SMB2 server sent bad RFC1001 len %d not %d\n"
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 967dfe6..e96a74d 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -209,6 +209,13 @@
return 0;
/*
+ * Some windows servers (win2016) will pad also the final
+ * PDU in a compound to 8 bytes.
+ */
+ if (((clc_len + 7) & ~7) == len)
+ return 0;
+
+ /*
* MacOS server pads after SMB2.1 write response with 3 bytes
* of junk. Other servers match RFC1001 len to actual
* SMB2/SMB3 frame length (header + smb2 response specific data)