[PATCH 3.16 44/72] CIFS: fix max ea value size

[Ben Hutchings]

3.16.79-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Murphy Zhou <jencce.kernel@xxxxxxxxx>

commit 63d37fb4ce5ae7bf1e58f906d1bf25f036fe79b2 upstream.

It should not be larger then the slab max buf size. If user
specifies a larger size, it passes this check and goes
straightly to SMB2_set_info_init performing an insecure memcpy.

Signed-off-by: Murphy Zhou <jencce.kernel@xxxxxxxxx>
Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/cifs/xattr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -29,7 +29,7 @@
 #include "cifsproto.h"
 #include "cifs_debug.h"
 
-#define MAX_EA_VALUE_SIZE 65535
+#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
 #define CIFS_XATTR_DOS_ATTRIB "user.DosAttrib"
 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl"