[PATCH] (2.6.24-rc8-mm1) -mm Smack socket label setting fix

From: Casey Schaufler
Date: Sat Jan 19 2008 - 13:40:03 EST


From: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

Correct the checks in smack_inode_setxattr to include the
socket labeling attributes. Simplify and correct
smack_sock_graft, while the values it was setting were
safe they were not correct and the job was not being
done efficiently. smack_inode_setsecurity wasn't
invoking the required netlabel function in the case
where smk_ipout was set. It does now, but that change
required the hook to be moved in the file. This
movement accounts for the bulk of the patch.


Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

---

security/smack/smack.h | 2
security/smack/smack_lsm.c | 136 ++++++++++++++++-------------------
2 files changed, 67 insertions(+), 71 deletions(-)

diff -uprN -X linux-2.6.24-rc8-mm1-base/Documentation/dontdiff linux-2.6.24-rc8-mm1-base/security/smack/smack.h linux-2.6.24-rc8-mm1-smack/security/smack/smack.h
--- linux-2.6.24-rc8-mm1-base/security/smack/smack.h 2008-01-18 14:12:26.000000000 -0800
+++ linux-2.6.24-rc8-mm1-smack/security/smack/smack.h 2008-01-18 15:09:43.000000000 -0800
@@ -130,6 +130,8 @@ struct smack_known {
#define XATTR_SMACK_IPIN "SMACK64IPIN"
#define XATTR_SMACK_IPOUT "SMACK64IPOUT"
#define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
+#define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN
+#define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT

/*
* smackfs macic number
diff -uprN -X linux-2.6.24-rc8-mm1-base/Documentation/dontdiff linux-2.6.24-rc8-mm1-base/security/smack/smack_lsm.c linux-2.6.24-rc8-mm1-smack/security/smack/smack_lsm.c
--- linux-2.6.24-rc8-mm1-base/security/smack/smack_lsm.c 2008-01-18 14:12:26.000000000 -0800
+++ linux-2.6.24-rc8-mm1-smack/security/smack/smack_lsm.c 2008-01-18 15:30:59.000000000 -0800
@@ -584,8 +584,12 @@ static int smack_inode_getattr(struct vf
static int smack_inode_setxattr(struct dentry *dentry, char *name,
void *value, size_t size, int flags)
{
- if (strcmp(name, XATTR_NAME_SMACK) == 0 && !capable(CAP_MAC_ADMIN))
+ if (!capable(CAP_MAC_ADMIN)) {
+ if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKIPOUT) == 0)
return -EPERM;
+ }

return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
}
@@ -718,57 +722,6 @@ static int smack_inode_getsecurity(const
return rc;
}

-/**
- * smack_inode_setsecurity - set smack xattrs
- * @inode: the object
- * @name: attribute name
- * @value: attribute value
- * @size: size of the attribute
- * @flags: unused
- *
- * Sets the named attribute in the appropriate blob
- *
- * Returns 0 on success, or an error code
- */
-static int smack_inode_setsecurity(struct inode *inode, const char *name,
- const void *value, size_t size, int flags)
-{
- char *sp;
- struct inode_smack *nsp = inode->i_security;
- struct socket_smack *ssp;
- struct socket *sock;
-
- if (value == NULL || size > SMK_LABELLEN)
- return -EACCES;
-
- sp = smk_import(value, size);
- if (sp == NULL)
- return -EINVAL;
-
- if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
- nsp->smk_inode = sp;
- return 0;
- }
- /*
- * The rest of the Smack xattrs are only on sockets.
- */
- if (inode->i_sb->s_magic != SOCKFS_MAGIC)
- return -EOPNOTSUPP;
-
- sock = SOCKET_I(inode);
- if (sock == NULL)
- return -EOPNOTSUPP;
-
- ssp = sock->sk->sk_security;
-
- if (strcmp(name, XATTR_SMACK_IPIN) == 0)
- ssp->smk_in = sp;
- else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
- ssp->smk_out = sp;
- else
- return -EOPNOTSUPP;
- return 0;
-}

/**
* smack_inode_listsecurity - list the Smack attributes
@@ -1341,6 +1294,60 @@ static int smack_netlabel(struct sock *s
}

/**
+ * smack_inode_setsecurity - set smack xattrs
+ * @inode: the object
+ * @name: attribute name
+ * @value: attribute value
+ * @size: size of the attribute
+ * @flags: unused
+ *
+ * Sets the named attribute in the appropriate blob
+ *
+ * Returns 0 on success, or an error code
+ */
+static int smack_inode_setsecurity(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ char *sp;
+ struct inode_smack *nsp = inode->i_security;
+ struct socket_smack *ssp;
+ struct socket *sock;
+
+ if (value == NULL || size > SMK_LABELLEN)
+ return -EACCES;
+
+ sp = smk_import(value, size);
+ if (sp == NULL)
+ return -EINVAL;
+
+ if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
+ nsp->smk_inode = sp;
+ return 0;
+ }
+ /*
+ * The rest of the Smack xattrs are only on sockets.
+ */
+ if (inode->i_sb->s_magic != SOCKFS_MAGIC)
+ return -EOPNOTSUPP;
+
+ sock = SOCKET_I(inode);
+ if (sock == NULL)
+ return -EOPNOTSUPP;
+
+ ssp = sock->sk->sk_security;
+
+ if (strcmp(name, XATTR_SMACK_IPIN) == 0)
+ ssp->smk_in = sp;
+ else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
+ ssp->smk_out = sp;
+ return smack_netlabel(sock->sk);
+ } else
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+/**
* smack_socket_post_create - finish socket setup
* @sock: the socket
* @family: protocol family
@@ -2192,33 +2199,20 @@ static int smack_socket_getpeersec_dgram
static void smack_sock_graft(struct sock *sk, struct socket *parent)
{
struct socket_smack *ssp;
- struct netlbl_lsm_secattr secattr;
- char smack[SMK_LABELLEN];
int rc;

- if (sk == NULL || parent == NULL || parent->sk == NULL)
+ if (sk == NULL)
return;

if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
return;

- ssp = parent->sk->sk_security;
-
- memset(smack, '\0', SMK_LABELLEN);
- netlbl_secattr_init(&secattr);
- rc = netlbl_sock_getattr(sk, &secattr);
- if (rc == 0)
- smack_from_secattr(&secattr, smack);
- else
- strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
- netlbl_secattr_destroy(&secattr);
-
- netlbl_secattr_init(&secattr);
+ ssp = sk->sk_security;
+ ssp->smk_in = current->security;
+ ssp->smk_out = current->security;
+ ssp->smk_packet[0] = '\0';

- smack_to_secattr(smack, &secattr);
- if (secattr.flags != NETLBL_SECATTR_NONE)
- rc = netlbl_sock_setattr(parent->sk, &secattr);
- netlbl_secattr_destroy(&secattr);
+ rc = smack_netlabel(sk);
}

/**


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