CRED: Pass credentials through dentry_open()

Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.

The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>

11 files changed, 37 insertions, 20 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 625abf5422e..ec16255d27d 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -307,7 +307,8 @@ static int autofs_dev_ioctl_open_mountpoint(const char *path, dev_t devid)
 			goto out;
 		}
 
-		filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY);
+		filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY,
+				   current_cred());
 		if (IS_ERR(filp)) {
 			err = PTR_ERR(filp);
 			goto out;
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 3504cf9df35..a75026d35d1 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -691,7 +691,8 @@ int ecryptfs_init_kthread(void);
 void ecryptfs_destroy_kthread(void);
 int ecryptfs_privileged_open(struct file **lower_file,
 			     struct dentry *lower_dentry,
-			     struct vfsmount *lower_mnt);
+			     struct vfsmount *lower_mnt,
+			     const struct cred *cred);
 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry);
 
 #endif /* #ifndef ECRYPTFS_KERNEL_H */
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index c440c6b58b2..c6d7a4d748a 100644
--- a/fs/ecryptfs/kthread.c
+++ b/fs/ecryptfs/kthread.c
@@ -73,7 +73,7 @@ static int ecryptfs_threadfn(void *ignored)
 				mntget(req->lower_mnt);
 				(*req->lower_file) = dentry_open(
 					req->lower_dentry, req->lower_mnt,
-					(O_RDWR | O_LARGEFILE));
+					(O_RDWR | O_LARGEFILE), current_cred());
 				req->flags |= ECRYPTFS_REQ_PROCESSED;
 			}
 			wake_up(&req->wait);
@@ -132,7 +132,8 @@ void ecryptfs_destroy_kthread(void)
  */
 int ecryptfs_privileged_open(struct file **lower_file,
 			     struct dentry *lower_dentry,
-			     struct vfsmount *lower_mnt)
+			     struct vfsmount *lower_mnt,
+			     const struct cred *cred)
 {
 	struct ecryptfs_open_req *req;
 	int rc = 0;
@@ -143,7 +144,7 @@ int ecryptfs_privileged_open(struct file **lower_file,
 	dget(lower_dentry);
 	mntget(lower_mnt);
 	(*lower_file) = dentry_open(lower_dentry, lower_mnt,
-				    (O_RDWR | O_LARGEFILE));
+				    (O_RDWR | O_LARGEFILE), cred);
 	if (!IS_ERR(*lower_file))
 		goto out;
 	req = kmem_cache_alloc(ecryptfs_open_req_cache, GFP_KERNEL);
@@ -184,7 +185,7 @@ int ecryptfs_privileged_open(struct file **lower_file,
 		dget(lower_dentry);
 		mntget(lower_mnt);
 		(*lower_file) = dentry_open(lower_dentry, lower_mnt,
-					    (O_RDONLY | O_LARGEFILE));
+					    (O_RDONLY | O_LARGEFILE), cred);
 		if (IS_ERR(*lower_file)) {
 			rc = PTR_ERR(*req->lower_file);
 			(*lower_file) = NULL;
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 64d2ba980df..fd630713c5c 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -115,6 +115,7 @@ void __ecryptfs_printk(const char *fmt, ...)
  */
 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 {
+	const struct cred *cred = current_cred();
 	struct ecryptfs_inode_info *inode_info =
 		ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
 	int rc = 0;
@@ -127,7 +128,7 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 
 		lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 		rc = ecryptfs_privileged_open(&inode_info->lower_file,
-						     lower_dentry, lower_mnt);
+					      lower_dentry, lower_mnt, cred);
 		if (rc || IS_ERR(inode_info->lower_file)) {
 			printk(KERN_ERR "Error opening lower persistent file "
 			       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 80246bad1b7..ec1fb918200 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
+#include <linux/sched.h>
 
 #define dprintk(fmt, args...) do{}while(0)
 
@@ -249,6 +250,7 @@ static int filldir_one(void * __buf, const char * name, int len,
 static int get_name(struct vfsmount *mnt, struct dentry *dentry,
 		char *name, struct dentry *child)
 {
+	const struct cred *cred = current_cred();
 	struct inode *dir = dentry->d_inode;
 	int error;
 	struct file *file;
@@ -263,7 +265,7 @@ static int get_name(struct vfsmount *mnt, struct dentry *dentry,
 	/*
 	 * Open the directory ...
 	 */
-	file = dentry_open(dget(dentry), mntget(mnt), O_RDONLY);
+	file = dentry_open(dget(dentry), mntget(mnt), O_RDONLY, cred);
 	error = PTR_ERR(file);
 	if (IS_ERR(file))
 		goto out;
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index 2b3d1828db9..795e2c130ad 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -426,6 +426,7 @@ static int file_mode(int fmode)
 
 static int hppfs_open(struct inode *inode, struct file *file)
 {
+	const struct cred *cred = current_cred();
 	struct hppfs_private *data;
 	struct vfsmount *proc_mnt;
 	struct dentry *proc_dentry;
@@ -446,7 +447,7 @@ static int hppfs_open(struct inode *inode, struct file *file)
 
 	/* XXX This isn't closed anywhere */
 	data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
-				      file_mode(file->f_mode));
+				      file_mode(file->f_mode), cred);
 	err = PTR_ERR(data->proc_file);
 	if (IS_ERR(data->proc_file))
 		goto out_free1;
@@ -489,6 +490,7 @@ static int hppfs_open(struct inode *inode, struct file *file)
 
 static int hppfs_dir_open(struct inode *inode, struct file *file)
 {
+	const struct cred *cred = current_cred();
 	struct hppfs_private *data;
 	struct vfsmount *proc_mnt;
 	struct dentry *proc_dentry;
@@ -502,7 +504,7 @@ static int hppfs_dir_open(struct inode *inode, struct file *file)
 	proc_dentry = HPPFS_I(inode)->proc_dentry;
 	proc_mnt = inode->i_sb->s_fs_info;
 	data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
-				      file_mode(file->f_mode));
+				      file_mode(file->f_mode), cred);
 	err = PTR_ERR(data->proc_file);
 	if (IS_ERR(data->proc_file))
 		goto out_free;
diff --git a/fs/nfsctl.c b/fs/nfsctl.c
index aed8145d908..cc4ef2642a5 100644
--- a/fs/nfsctl.c
+++ b/fs/nfsctl.c
@@ -41,7 +41,8 @@ static struct file *do_open(char *name, int flags)
 		error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
 
 	if (!error)
-		return dentry_open(nd.path.dentry, nd.path.mnt, flags);
+		return dentry_open(nd.path.dentry, nd.path.mnt, flags,
+				   current_cred());
 
 	path_put(&nd.path);
 	return ERR_PTR(error);
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index a5e14e8695e..632a50b4b37 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -226,7 +226,8 @@ nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
 
 	nfs4_save_user(&uid, &gid);
 
-	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY);
+	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
+			   current_cred());
 	status = PTR_ERR(filp);
 	if (IS_ERR(filp))
 		goto out;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 890d9a68c85..b59ec5a6ed2 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -671,6 +671,7 @@ __be32
 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 			int access, struct file **filp)
 {
+	const struct cred *cred = current_cred();
 	struct dentry	*dentry;
 	struct inode	*inode;
 	int		flags = O_RDONLY|O_LARGEFILE;
@@ -725,7 +726,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 		DQUOT_INIT(inode);
 	}
 	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
-				flags);
+			    flags, cred);
 	if (IS_ERR(*filp))
 		host_err = PTR_ERR(*filp);
 out_nfserr:
diff --git a/fs/open.c b/fs/open.c
index b1238e195e7..f96eaab280a 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -783,7 +783,8 @@ static inline int __get_file_write_access(struct inode *inode,
 
 static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 					int flags, struct file *f,
-					int (*open)(struct inode *, struct file *))
+					int (*open)(struct inode *, struct file *),
+					const struct cred *cred)
 {
 	struct inode *inode;
 	int error;
@@ -807,7 +808,7 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 	f->f_op = fops_get(inode->i_fop);
 	file_move(f, &inode->i_sb->s_files);
 
-	error = security_dentry_open(f);
+	error = security_dentry_open(f, cred);
 	if (error)
 		goto cleanup_all;
 
@@ -882,6 +883,8 @@ cleanup_file:
 struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
 		int (*open)(struct inode *, struct file *))
 {
+	const struct cred *cred = current_cred();
+
 	if (IS_ERR(nd->intent.open.file))
 		goto out;
 	if (IS_ERR(dentry))
@@ -889,7 +892,7 @@ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry
 	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
 					     nd->intent.open.flags - 1,
 					     nd->intent.open.file,
-					     open);
+					     open, cred);
 out:
 	return nd->intent.open.file;
 out_err:
@@ -908,6 +911,7 @@ EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
  */
 struct file *nameidata_to_filp(struct nameidata *nd, int flags)
 {
+	const struct cred *cred = current_cred();
 	struct file *filp;
 
 	/* Pick up the filp from the open intent */
@@ -915,7 +919,7 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags)
 	/* Has the filesystem initialised the file for us? */
 	if (filp->f_path.dentry == NULL)
 		filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
-				     NULL);
+				     NULL, cred);
 	else
 		path_put(&nd->path);
 	return filp;
@@ -925,7 +929,8 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags)
  * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
  * error.
  */
-struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
+			 const struct cred *cred)
 {
 	int error;
 	struct file *f;
@@ -950,7 +955,7 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
 		return ERR_PTR(error);
 	}
 
-	return __dentry_open(dentry, mnt, flags, f, NULL);
+	return __dentry_open(dentry, mnt, flags, f, NULL, cred);
 }
 EXPORT_SYMBOL(dentry_open);
 
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 67c72aec97e..281cbd5a25c 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -256,6 +256,7 @@ xfs_open_by_handle(
 	struct file		*parfilp,
 	struct inode		*parinode)
 {
+	const struct cred	*cred = current_cred();
 	int			error;
 	int			new_fd;
 	int			permflag;
@@ -321,7 +322,7 @@ xfs_open_by_handle(
 	mntget(parfilp->f_path.mnt);
 
 	/* Create file pointer. */
-	filp = dentry_open(dentry, parfilp->f_path.mnt, hreq.oflags);
+	filp = dentry_open(dentry, parfilp->f_path.mnt, hreq.oflags, cred);
 	if (IS_ERR(filp)) {
 		put_unused_fd(new_fd);
 		return -XFS_ERROR(-PTR_ERR(filp));