LSM: split LSM_AUDIT_DATA_FS into _PATH and _INODE

The lsm common audit code has wacky contortions making sure which pieces
of information are set based on if it was given a path, dentry, or
inode.  Split this into path and inode to get rid of some of the code
complexity.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

5 files changed, 74 insertions, 68 deletions

diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 908aa712816a..2e846052cbf4 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -210,7 +210,6 @@ static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
 static void dump_common_audit_data(struct audit_buffer *ab,
                                    struct common_audit_data *a)
 {
-        struct inode *inode = NULL;
         struct task_struct *tsk = current;
 
         if (a->tsk)
@@ -229,33 +228,40 @@ static void dump_common_audit_data(struct audit_buffer *ab,
         case LSM_AUDIT_DATA_CAP:
                 audit_log_format(ab, " capability=%d ", a->u.cap);
                 break;
-        case LSM_AUDIT_DATA_FS:
-                if (a->u.fs.path.dentry) {
-                        struct dentry *dentry = a->u.fs.path.dentry;
-                        if (a->u.fs.path.mnt) {
-                                audit_log_d_path(ab, "path=", &a->u.fs.path);
-                        } else {
-                                audit_log_format(ab, " name=");
-                                audit_log_untrustedstring(ab,
-                                                 dentry->d_name.name);
-                        }
-                        inode = dentry->d_inode;
-                } else if (a->u.fs.inode) {
-                        struct dentry *dentry;
-                        inode = a->u.fs.inode;
-                        dentry = d_find_alias(inode);
-                        if (dentry) {
-                                audit_log_format(ab, " name=");
-                                audit_log_untrustedstring(ab,
-                                                 dentry->d_name.name);
-                                dput(dentry);
-                        }
+        case LSM_AUDIT_DATA_PATH: {
+                struct dentry *dentry = a->u.path.dentry;
+                struct inode *inode;
+
+                if (a->u.path.mnt) {
+                        audit_log_d_path(ab, "path=", &a->u.path);
+                } else {
+                        audit_log_format(ab, " name=");
+                        audit_log_untrustedstring(ab,
+                                         dentry->d_name.name);
                 }
+                inode = dentry->d_inode;
                 if (inode)
                         audit_log_format(ab, " dev=%s ino=%lu",
                                         inode->i_sb->s_id,
                                         inode->i_ino);
                 break;
+        }
+        case LSM_AUDIT_DATA_INODE: {
+                struct dentry *dentry;
+                struct inode *inode;
+
+                inode = a->u.inode;
+                dentry = d_find_alias(inode);
+                if (dentry) {
+                        audit_log_format(ab, " name=");
+                        audit_log_untrustedstring(ab,
+                                         dentry->d_name.name);
+                        dput(dentry);
+                }
+                audit_log_format(ab, " dev=%s ino=%lu", inode->i_sb->s_id,
+                                 inode->i_ino);
+                break;
+        }
         case LSM_AUDIT_DATA_TASK:
                 tsk = a->u.tsk;
                 if (tsk && tsk->pid) {
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1d027e29ce8d..ce742f1778e1 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -531,7 +531,7 @@ int avc_audit(u32 ssid, u32 tsid,
          * during retry. However this is logically just as if the operation
          * happened a little later.
          */
-        if ((a->type == LSM_AUDIT_DATA_FS) &&
+        if ((a->type == LSM_AUDIT_DATA_INODE) &&
             (flags & IPERM_FLAG_RCU))
                 return -ECHILD;
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ed5f29aa0a38..ad664d3056eb 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1488,8 +1488,8 @@ static int inode_has_perm(const struct cred *cred,
 
         if (!adp) {
                 adp = &ad;
-                COMMON_AUDIT_DATA_INIT(&ad, FS);
-                ad.u.fs.inode = inode;
+                COMMON_AUDIT_DATA_INIT(&ad, INODE);
+                ad.u.inode = inode;
         }
 
         return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
@@ -1506,9 +1506,9 @@ static inline int dentry_has_perm(const struct cred *cred,
         struct inode *inode = dentry->d_inode;
         struct common_audit_data ad;
 
-        COMMON_AUDIT_DATA_INIT(&ad, FS);
-        ad.u.fs.path.mnt = mnt;
-        ad.u.fs.path.dentry = dentry;
+        COMMON_AUDIT_DATA_INIT(&ad, PATH);
+        ad.u.path.mnt = mnt;
+        ad.u.path.dentry = dentry;
         return inode_has_perm(cred, inode, av, &ad, 0);
 }
 
@@ -1530,8 +1530,8 @@ static int file_has_perm(const struct cred *cred,
         u32 sid = cred_sid(cred);
         int rc;
 
-        COMMON_AUDIT_DATA_INIT(&ad, FS);
-        ad.u.fs.path = file->f_path;
+        COMMON_AUDIT_DATA_INIT(&ad, PATH);
+        ad.u.path = file->f_path;
 
         if (sid != fsec->sid) {
                 rc = avc_has_perm(sid, fsec->sid,
@@ -1569,8 +1569,8 @@ static int may_create(struct inode *dir,
         sid = tsec->sid;
         newsid = tsec->create_sid;
 
-        COMMON_AUDIT_DATA_INIT(&ad, FS);
-        ad.u.fs.path.dentry = dentry;
+        COMMON_AUDIT_DATA_INIT(&ad, PATH);
+        ad.u.path.dentry = dentry;
 
         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
                           DIR__ADD_NAME | DIR__SEARCH,
@@ -1621,8 +1621,8 @@ static int may_link(struct inode *dir,
         dsec = dir->i_security;
         isec = dentry->d_inode->i_security;
 
-        COMMON_AUDIT_DATA_INIT(&ad, FS);
-        ad.u.fs.path.dentry = dentry;
+        COMMON_AUDIT_DATA_INIT(&ad, PATH);
+        ad.u.path.dentry = dentry;
 
         av = DIR__SEARCH;
         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
@@ -1667,9 +1667,9 @@ static inline int may_rename(struct inode *old_dir,
         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
         new_dsec = new_dir->i_security;
 
-        COMMON_AUDIT_DATA_INIT(&ad, FS);
+        COMMON_AUDIT_DATA_INIT(&ad, PATH);
 
-        ad.u.fs.path.dentry = old_dentry;
+        ad.u.path.dentry = old_dentry;
         rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
         if (rc)
@@ -1685,7 +1685,7 @@ static inline int may_rename(struct inode *old_dir,
                         return rc;
         }
 
-        ad.u.fs.path.dentry = new_dentry;
+        ad.u.path.dentry = new_dentry;
         av = DIR__ADD_NAME | DIR__SEARCH;
         if (new_dentry->d_inode)
                 av |= DIR__REMOVE_NAME;
@@ -1991,8 +1991,8 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
                         return rc;