Smack: Abstract use of inode security blob

Don't use the inode->i_security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 2007d38d0e46d0c385773197fe841d36cf072481..436231dfae333451ea680529f57c226ee471c706 100644 (file)
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -368,12 +368,17 @@ static inline struct smack_known **smack_file(const struct file *file)
                                       smack_blob_sizes.lbs_file);
 }
 
+static inline struct inode_smack *smack_inode(const struct inode *inode)
+{
+       return inode->i_security;
+}
+
 /*
  * Is the directory transmuting?
  */
 static inline int smk_inode_transmutable(const struct inode *isp)
 {
-       struct inode_smack *sip = isp->i_security;
+       struct inode_smack *sip = smack_inode(isp);
        return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
 }
 
@@ -382,7 +387,7 @@ static inline int smk_inode_transmutable(const struct inode *isp)
  */
 static inline struct smack_known *smk_of_inode(const struct inode *isp)
 {
-       struct inode_smack *sip = isp->i_security;
+       struct inode_smack *sip = smack_inode(isp);
        return sip->smk_inode;
 }
 

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7c76668ea3a6782bc9b7ff4c7418c14e95806e26..ddffda39d10713d5f52f3335a281c28570d08ab5 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -183,7 +183,7 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
 static int smk_bu_inode(struct inode *inode, int mode, int rc)
 {
        struct task_smack *tsp = smack_cred(current_cred());
-       struct inode_smack *isp = inode->i_security;
+       struct inode_smack *isp = smack_inode(inode);
        char acc[SMK_NUM_ACCESS_TYPE + 1];
 
        if (isp->smk_flags & SMK_INODE_IMPURE)
@@ -215,7 +215,7 @@ static int smk_bu_file(struct file *file, int mode, int rc)
        struct task_smack *tsp = smack_cred(current_cred());
        struct smack_known *sskp = tsp->smk_task;
        struct inode *inode = file_inode(file);
-       struct inode_smack *isp = inode->i_security;
+       struct inode_smack *isp = smack_inode(inode);
        char acc[SMK_NUM_ACCESS_TYPE + 1];
 
        if (isp->smk_flags & SMK_INODE_IMPURE)
@@ -245,7 +245,7 @@ static int smk_bu_credfile(const struct cred *cred, struct file *file,
        struct task_smack *tsp = smack_cred(cred);
        struct smack_known *sskp = tsp->smk_task;
        struct inode *inode = file_inode(file);
-       struct inode_smack *isp = inode->i_security;
+       struct inode_smack *isp = smack_inode(inode);
        char acc[SMK_NUM_ACCESS_TYPE + 1];
 
        if (isp->smk_flags & SMK_INODE_IMPURE)
@@ -773,7 +773,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
        /*
         * Initialize the root inode.
         */
-       isp = inode->i_security;
+       isp = smack_inode(inode);
        if (isp == NULL) {
                isp = new_inode_smack(sp->smk_root);
                if (isp == NULL)
@@ -830,7 +830,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
        if (bprm->called_set_creds)
                return 0;
 
-       isp = inode->i_security;
+       isp = smack_inode(inode);
        if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
                return 0;
 
@@ -910,7 +910,7 @@ static void smack_inode_free_rcu(struct rcu_head *head)
  */
 static void smack_inode_free_security(struct inode *inode)
 {
-       struct inode_smack *issp = inode->i_security;
+       struct inode_smack *issp = smack_inode(inode);
 
        /*
         * The inode may still be referenced in a path walk and
@@ -938,7 +938,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
                                     const struct qstr *qstr, const char **name,
                                     void **value, size_t *len)
 {
-       struct inode_smack *issp = inode->i_security;
+       struct inode_smack *issp = smack_inode(inode);
        struct smack_known *skp = smk_of_current();
        struct smack_known *isp = smk_of_inode(inode);
        struct smack_known *dsp = smk_of_inode(dir);
@@ -1276,7 +1276,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
                                      const void *value, size_t size, int flags)
 {
        struct smack_known *skp;
-       struct inode_smack *isp = d_backing_inode(dentry)->i_security;
+       struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
 
        if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
                isp->smk_flags |= SMK_INODE_TRANSMUTE;
@@ -1357,7 +1357,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
        if (rc != 0)
                return rc;
 
-       isp = d_backing_inode(dentry)->i_security;
+       isp = smack_inode(d_backing_inode(dentry));
        /*
         * Don't do anything special for these.
         *      XATTR_NAME_SMACKIPIN
@@ -1632,7 +1632,7 @@ static int smack_mmap_file(struct file *file,
        if (unlikely(IS_PRIVATE(file_inode(file))))
                return 0;
 
-       isp = file_inode(file)->i_security;
+       isp = smack_inode(file_inode(file));
        if (isp->smk_mmap == NULL)
                return 0;
        sbsp = file_inode(file)->i_sb->s_security;
@@ -1979,7 +1979,7 @@ static int smack_kernel_act_as(struct cred *new, u32 secid)
 static int smack_kernel_create_files_as(struct cred *new,
                                        struct inode *inode)
 {
-       struct inode_smack *isp = inode->i_security;
+       struct inode_smack *isp = smack_inode(inode);
        struct task_smack *tsp = smack_cred(new);
 
        tsp->smk_forked = isp->smk_inode;
@@ -2179,7 +2179,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
  */
 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
 {
-       struct inode_smack *isp = inode->i_security;
+       struct inode_smack *isp = smack_inode(inode);
        struct smack_known *skp = smk_of_task_struct(p);
 
        isp->smk_inode = skp;
@@ -2642,7 +2642,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
                                   const void *value, size_t size, int flags)
 {
        struct smack_known *skp;
-       struct inode_smack *nsp = inode->i_security;
+       struct inode_smack *nsp = smack_inode(inode);
        struct socket_smack *ssp;
        struct socket *sock;
        int rc = 0;
@@ -3250,7 +3250,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
        if (inode == NULL)
                return;
 
-       isp = inode->i_security;
+       isp = smack_inode(inode);
 
        mutex_lock(&isp->smk_lock);
        /*
@@ -4488,7 +4488,7 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
        /*
         * Get label from overlay inode and set it in create_sid
         */
-       isp = d_inode(dentry->d_parent)->i_security;
+       isp = smack_inode(d_inode(dentry->d_parent));
        skp = isp->smk_inode;
        tsp->smk_task = skp;
        *new = new_creds;
@@ -4525,7 +4525,7 @@ static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
        /*
         * the attribute of the containing directory
         */
-       isp = d_inode(dentry->d_parent)->i_security;
+       isp = smack_inode(d_inode(dentry->d_parent));
 
        if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
                rcu_read_lock();