From: Steve French <stfrench@microsoft.com>
Date: Wed, 29 Aug 2018 09:22:22 -0500
Subject: [PATCH] smb3: minor debugging clarifications in rfc1001 len
processing
Git-commit: 25f2573512d7b38bca4c0878109db9600b8b711f
Patch-mainline: v4.19-rc3
References: bsc#1144333
I ran into some cases where server was returning the wrong length
on frames but I couldn't easily match them to the command in the
network trace (or server logs) since I need the command and/or
multiplex id to find the offending SMB2/SMB3 command. Add these
two fields to the log message. In the case of padding too much
it may not be a problem in all cases but might have correlated
to a network disconnect case in some problems we have been
looking at. In the case of frame too short is even more important.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/smb2misc.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index db0453660ff6..6a9c47541c53 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -248,16 +248,20 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
* 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)
- * Some windows servers do too when compounding is used.
- * Log the server error (once), but allow it and continue
+ * Some windows servers also pad up to 8 bytes when compounding.
+ * If pad is longer than eight bytes, log the server behavior
+ * (once), since may indicate a problem but allow it and continue
* since the frame is parseable.
*/
if (clc_len < len) {
- printk_once(KERN_WARNING
- "SMB2 server sent bad RFC1001 len %d not %d\n",
- len, clc_len);
+ pr_warn_once(
+ "srv rsp padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
+ len, clc_len, command, mid);
return 0;
}
+ pr_warn_once(
+ "srv rsp too short, len %d not %d. cmd:%d mid:%llu\n",
+ len, clc_len, command, mid);
return 1;
}
--
2.16.4