BACKPORT: 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.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
(cherry-picked from upstream da1b63566c469bf3e2b24182114422e16b1aa34c)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index cce68ea84d6c6001a2c71c855ab0ac66cc0a309c..3080620b12c34288a03af56d963d3625cfe500e0 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -675,7 +675,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
        }
 
        if (len)
-               *len = strlen(isp) + 1;
+               *len = strlen(isp);
 
        return 0;
 }
@@ -1079,7 +1079,7 @@ 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;
        }
@@ -1104,7 +1104,7 @@ 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;