[PATCH 3/3] Smack: remove unneeded NULL-termination from securtity label

From: Konstantin Khlebnikov
Date: Thu Aug 07 2014 - 12:52:58 EST


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@xxxxxxxxxxx>
---
security/smack/smack_lsm.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index afa5ad0..16ae853 100644
--- 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;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/