From e6c47dd0da1e3a484e778046fc10da0b20606a86 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Wed, 22 Aug 2018 12:19:24 +1000 Subject: [PATCH] cifs: check if SMB2 PDU size has been padded and suppress the warning 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 Signed-off-by: Steve French --- fs/cifs/smb2misc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 303d459..db045366 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -238,6 +238,13 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr) 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) -- 2.7.4