Smack: remove unneeded NULL-termination from securtity label

Values of extended attributes are stored as binary blobs. NULL-termination
of them isn't required. It just wastes disk space and confuses command-line
tools like getfattr because they have to print that zero byte at the end.

This patch removes terminating zero byte from initial security label in
smack_inode_init_security and cuts it out in function smack_inode_getsecurity
which is used by syscall getxattr. This change seems completely safe, because
function smk_parse_smack ignores everything after first zero byte.

Change-Id: I131879e36fc9e71b65857b46714ccd0e512fc83c
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
(cherry picked from commit a99ae8658f4402b6ecdd62cd5414e32356aa3025)

Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7bd0363..d347b79 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -672,7 +672,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
        }
 
        if (len)
-               *len = strlen(isp) + 1;
+               *len = strlen(isp);
 
        return 0;
 }
@@ -1076,7 +1076,7 @@ static int smack_inode_getsecurity(const struct inode *inode,
 
        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
                isp = smk_of_inode(inode);
-               ilen = strlen(isp) + 1;
+               ilen = strlen(isp);
                *buffer = isp;
                return ilen;
        }
@@ -1101,7 +1101,7 @@ static int smack_inode_getsecurity(const struct inode *inode,
        else
                return -EOPNOTSUPP;
 
-       ilen = strlen(isp) + 1;
+       ilen = strlen(isp);
        if (rc == 0) {
                *buffer = isp;
                rc = ilen;