smb: client: fix parsing of SMB3.1.1 POSIX create context

The data offset for the SMB3.1.1 POSIX create context will always be
8-byte aligned so having the check 'noff + nlen >= doff' in
smb2_parse_contexts() is wrong as it will lead to -EINVAL because noff
+ nlen == doff.

Fix the sanity check to correctly handle aligned create context data.

Fixes: af1689a9b770 ("smb: client: fix potential OOBs in smb2_parse_contexts()")
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index f8d70660ba2926f736e92fbb682df8331799048e..ec39dfbc315417fafd189d8dc3fc5c44e3d6a993 100644 (file)
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -2277,7 +2277,7 @@ int smb2_parse_contexts(struct TCP_Server_Info *server,
 
                noff = le16_to_cpu(cc->NameOffset);
                nlen = le16_to_cpu(cc->NameLength);
-               if (noff + nlen >= doff)
+               if (noff + nlen > doff)
                        return -EINVAL;
 
                name = (char *)cc + noff;