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>

6 files changed, 78 insertions, 73 deletions

diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 112a550..bbaceab 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -27,7 +27,7 @@
 /* Auxiliary data to use in generating the audit record. */
 struct common_audit_data {
 	char type;
-#define LSM_AUDIT_DATA_FS	1
+#define LSM_AUDIT_DATA_PATH	1
 #define LSM_AUDIT_DATA_NET	2
 #define LSM_AUDIT_DATA_CAP	3
 #define LSM_AUDIT_DATA_IPC	4
@@ -35,12 +35,11 @@ struct common_audit_data {
 #define LSM_AUDIT_DATA_KEY	6
 #define LSM_AUDIT_DATA_NONE	7
 #define LSM_AUDIT_DATA_KMOD	8
+#define LSM_AUDIT_DATA_INODE	9
 	struct task_struct *tsk;
 	union 	{
-		struct {
-			struct path path;
-			struct inode *inode;
-		} fs;
+		struct path path;
+		struct inode *inode;
 		struct {
 			int netif;
 			struct sock *sk;
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 908aa71..2e84605 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 1d027e2..ce742f1 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 ed5f29a..ad664d3 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;
 	}
 
-	COMMON_AUDIT_DATA_INIT(&ad, FS);
-	ad.u.fs.path = bprm->file->f_path;
+	COMMON_AUDIT_DATA_INIT(&ad, PATH);
+	ad.u.path = bprm->file->f_path;
 
 	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
 		new_tsec->sid = old_tsec->sid;
@@ -2120,7 +2120,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 
 	/* Revalidate access to inherited open files. */
 
-	COMMON_AUDIT_DATA_INIT(&ad, FS);
+	COMMON_AUDIT_DATA_INIT(&ad, INODE);
 
 	spin_lock(&files->file_lock);
 	for (;;) {
@@ -2468,8 +2468,8 @@ static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
 	if (flags & MS_KERNMOUNT)
 		return 0;
 
-	COMMON_AUDIT_DATA_INIT(&ad, FS);
-	ad.u.fs.path.dentry = sb->s_root;
+	COMMON_AUDIT_DATA_INIT(&ad, PATH);
+	ad.u.path.dentry = sb->s_root;
 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
 }
 
@@ -2478,8 +2478,8 @@ static int selinux_sb_statfs(struct dentry *dentry)
 	const struct cred *cred = current_cred();
 	struct common_audit_data ad;
 
-	COMMON_AUDIT_DATA_INIT(&ad, FS);
-	ad.u.fs.path.dentry = dentry->d_sb->s_root;
+	COMMON_AUDIT_DATA_INIT(&ad, PATH);
+	ad.u.path.dentry = dentry->d_sb->s_root;
 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
 }
 
@@ -2653,8 +2653,8 @@ static int selinux_inode_permission(struct inode *inode, int mask, unsigned flag
 	if (!mask)
 		return 0;
 
-	COMMON_AUDIT_DATA_INIT(&ad, FS);
-	ad.u.fs.inode = inode;
+	COMMON_AUDIT_DATA_INIT(&ad, INODE);
+	ad.u.inode = inode;
 
 	if (from_access)
 		ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
@@ -2732,8 +2732,8 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
 	if (!is_owner_or_cap(inode))
 		return -EPERM;
 
-	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, isec->sid, isec->sclass,
 			  FILE__RELABELFROM, &ad);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index b449cfd..a16925c 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -316,22 +316,22 @@ static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
 						    struct dentry *d)
 {
-	a->a.u.fs.path.dentry = d;
+	a->a.u.path.dentry = d;
 }
 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a,
 						 struct vfsmount *m)
 {
-	a->a.u.fs.path.mnt = m;
+	a->a.u.path.mnt = m;
 }
 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
 					      struct inode *i)
 {
-	a->a.u.fs.inode = i;
+	a->a.u.inode = i;
 }
 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
 					     struct path p)
 {
-	a->a.u.fs.path = p;
+	a->a.u.path = p;
 }
 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
 					    struct sock *sk)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 42fcb47..eeb393f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -383,7 +383,7 @@ static int smack_sb_statfs(struct dentry *dentry)
 	int rc;
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
@@ -407,7 +407,7 @@ static int smack_sb_mount(char *dev_name, struct path *path,
 	struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path(&ad, *path);
 
 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
@@ -426,7 +426,7 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags)
 	struct superblock_smack *sbp;
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, mnt->mnt_root);
 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
 
@@ -563,7 +563,7 @@ static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
 	struct smk_audit_info ad;
 	int rc;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 
 	isp = smk_of_inode(old_dentry->d_inode);
@@ -592,7 +592,7 @@ static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
 	struct smk_audit_info ad;
 	int rc;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	/*
@@ -623,7 +623,7 @@ static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
 	struct smk_audit_info ad;
 	int rc;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	/*
@@ -663,7 +663,7 @@ static int smack_inode_rename(struct inode *old_inode,
 	char *isp;
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 
 	isp = smk_of_inode(old_dentry->d_inode);
@@ -700,7 +700,7 @@ static int smack_inode_permission(struct inode *inode, int mask, unsigned flags)
 	/* May be droppable after audit */
 	if (flags & IPERM_FLAG_RCU)
 		return -ECHILD;
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
 	smk_ad_setfield_u_fs_inode(&ad, inode);
 	return smk_curacc(smk_of_inode(inode), mask, &ad);
 }
@@ -720,7 +720,7 @@ static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
 	 */
 	if (iattr->ia_valid & ATTR_FORCE)
 		return 0;
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
@@ -737,7 +737,7 @@ static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 {
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
@@ -784,7 +784,7 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 	} else
 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	if (rc == 0)
@@ -845,7 +845,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name)
 {
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 
 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
@@ -877,7 +877,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 	} else
 		rc = cap_inode_removexattr(dentry, name);
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 	if (rc == 0)
 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
@@ -1047,7 +1047,7 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd,
 	int rc = 0;
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
 
 	if (_IOC_DIR(cmd) & _IOC_WRITE)
@@ -1070,7 +1070,7 @@ static int smack_file_lock(struct file *file, unsigned int cmd)
 {
 	struct smk_audit_info ad;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path_dentry(&ad, file->f_path.dentry);
 	return smk_curacc(file->f_security, MAY_WRITE, &ad);
 }
@@ -1089,7 +1089,7 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
 	struct smk_audit_info ad;
 	int rc;
 
-	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
+	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
 
 	switch (cmd) {