smack: fix logic in smack_inode_init_security function

In principle if this function was called with "value" == NULL and "len"
not NULL it could return different results for the "len" compared to a
case where "name" was not NULL. This is a hypothetical case that does
not exist in the kernel, but it's a logic bug nonetheless.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index dcfaddd955d1..048d92e81a34 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -800,7 +800,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
         if (name)
                 *name = XATTR_SMACK_SUFFIX;
 
-        if (value) {
+        if (value && len) {
                 rcu_read_lock();
                 may = smk_access_entry(skp->smk_known, dsp->smk_known,
                                        &skp->smk_rules);
@@ -821,10 +821,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
                 *value = kstrdup(isp->smk_known, GFP_NOFS);
                 if (*value == NULL)
                         return -ENOMEM;
-        }
 
-        if (len)
                 *len = strlen(isp->smk_known);
+        }
 
         return 0;
 }