fs/vfs/security: pass last path component to LSM on inode creation

SELinux would like to implement a new labeling behavior of newly created
inodes.  We currently label new inodes based on the parent and the creating
process.  This new behavior would also take into account the name of the
new object when deciding the new label.  This is not the (supposed) full path,
just the last component of the path.

This is very useful because creating /etc/shadow is different than creating
/etc/passwd but the kernel hooks are unable to differentiate these
operations.  We currently require that userspace realize it is doing some
difficult operation like that and than userspace jumps through SELinux hoops
to get things set up correctly.  This patch does not implement new
behavior, that is obviously contained in a seperate SELinux patch, but it
does pass the needed name down to the correct LSM hook.  If no such name
exists it is fine to pass NULL.

Signed-off-by: Eric Paris <eparis@redhat.com>

5 files changed, 21 insertions, 18 deletions

diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 9297865..82faddd 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -215,8 +215,7 @@ static int jffs2_create(struct inode *dir_i, struct dentry *dentry, int mode,
 	   no chance of AB-BA deadlock involving its f->sem). */
 	mutex_unlock(&f->sem);
 
-	ret = jffs2_do_create(c, dir_f, f, ri,
-			      dentry->d_name.name, dentry->d_name.len);
+	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
 	if (ret)
 		goto fail;
 
@@ -386,7 +385,7 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
 
 	jffs2_complete_reservation(c);
 
-	ret = jffs2_init_security(inode, dir_i);
+	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 	if (ret)
 		goto fail;
 
@@ -530,7 +529,7 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
 
 	jffs2_complete_reservation(c);
 
-	ret = jffs2_init_security(inode, dir_i);
+	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 	if (ret)
 		goto fail;
 
@@ -703,7 +702,7 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, de
 
 	jffs2_complete_reservation(c);
 
-	ret = jffs2_init_security(inode, dir_i);
+	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 	if (ret)
 		goto fail;
 
diff --git a/fs/jffs2/nodelist.h b/fs/jffs2/nodelist.h
index 5a53d9b..e4619b0 100644
--- a/fs/jffs2/nodelist.h
+++ b/fs/jffs2/nodelist.h
@@ -401,7 +401,7 @@ int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 			    struct jffs2_raw_inode *ri, unsigned char *buf,
 			    uint32_t offset, uint32_t writelen, uint32_t *retlen);
 int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,
-		    struct jffs2_raw_inode *ri, const char *name, int namelen);
+		    struct jffs2_raw_inode *ri, const struct qstr *qstr);
 int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
 		    int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
 int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index 239f512..cfeb716 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -23,14 +23,15 @@
 #include "nodelist.h"
 
 /* ---- Initial Security Label Attachment -------------- */
-int jffs2_init_security(struct inode *inode, struct inode *dir)
+int jffs2_init_security(struct inode *inode, struct inode *dir,
+			const struct qstr *qstr)
 {
 	int rc;
 	size_t len;
 	void *value;
 	char *name;
 
-	rc = security_inode_init_security(inode, dir, &name, &value, &len);
+	rc = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
 	if (rc) {
 		if (rc == -EOPNOTSUPP)
 			return 0;
diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c
index c819eb0..30d175b 100644
--- a/fs/jffs2/write.c
+++ b/fs/jffs2/write.c
@@ -424,7 +424,9 @@ int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 	return ret;
 }
 
-int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f, struct jffs2_raw_inode *ri, const char *name, int namelen)
+int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f,
+		    struct jffs2_inode_info *f, struct jffs2_raw_inode *ri,
+		    const struct qstr *qstr)
 {
 	struct jffs2_raw_dirent *rd;
 	struct jffs2_full_dnode *fn;
@@ -466,15 +468,15 @@ int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, str
 	mutex_unlock(&f->sem);
 	jffs2_complete_reservation(c);
 
-	ret = jffs2_init_security(&f->vfs_inode, &dir_f->vfs_inode);
+	ret = jffs2_init_security(&f->vfs_inode, &dir_f->vfs_inode, qstr);
 	if (ret)
 		return ret;
 	ret = jffs2_init_acl_post(&f->vfs_inode);
 	if (ret)
 		return ret;
 
-	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
-				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
+	ret = jffs2_reserve_space(c, sizeof(*rd)+qstr->len, &alloclen,
+				ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(qstr->len));
 
 	if (ret) {
 		/* Eep. */
@@ -493,19 +495,19 @@ int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, str
 
 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
-	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
+	rd->totlen = cpu_to_je32(sizeof(*rd) + qstr->len);
 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 
 	rd->pino = cpu_to_je32(dir_f->inocache->ino);
 	rd->version = cpu_to_je32(++dir_f->highest_version);
 	rd->ino = ri->ino;
 	rd->mctime = ri->ctime;
-	rd->nsize = namelen;
+	rd->nsize = qstr->len;
 	rd->type = DT_REG;
 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
-	rd->name_crc = cpu_to_je32(crc32(0, name, namelen));
+	rd->name_crc = cpu_to_je32(crc32(0, qstr->name, qstr->len));
 
-	fd = jffs2_write_dirent(c, dir_f, rd, name, namelen, ALLOC_NORMAL);
+	fd = jffs2_write_dirent(c, dir_f, rd, qstr->name, qstr->len, ALLOC_NORMAL);
 
 	jffs2_free_raw_dirent(rd);
 
diff --git a/fs/jffs2/xattr.h b/fs/jffs2/xattr.h
index cf4f575..7be4beb 100644
--- a/fs/jffs2/xattr.h
+++ b/fs/jffs2/xattr.h
@@ -121,10 +121,11 @@ extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t);
 #endif /* CONFIG_JFFS2_FS_XATTR */
 
 #ifdef CONFIG_JFFS2_FS_SECURITY
-extern int jffs2_init_security(struct inode *inode, struct inode *dir);
+extern int jffs2_init_security(struct inode *inode, struct inode *dir,
+			       const struct qstr *qstr);
 extern const struct xattr_handler jffs2_security_xattr_handler;
 #else
-#define jffs2_init_security(inode,dir)	(0)
+#define jffs2_init_security(inode,dir,qstr)	(0)
 #endif /* CONFIG_JFFS2_FS_SECURITY */
 
 #endif /* _JFFS2_FS_XATTR_H_ */